hel
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Gọi `D` là trung điểm của `BH`
Kẻ `DF` vuông góc `AB` tại `D;DF=AB`
Xét `\triangleFDB` và `\triangleBAC`:
`DF=AB`
`\hat{FDB}=\hat{BAC}=90^o`
`DB=AC`
`=>\triangleFDB=\triangleBAC{c.g.c)`
`=>FB=BC;\hat{FBD}=\hat{BCA}`
`=>\hat{FBD}=90^o - \hat{ABC}=15^o`
`=>\hat{FBC}=\hat{ABC} - \hat{FBD} = 60^o`
Xét `\triangleBFC`, có: `FB=BC=>\triangleBFC` cân tại `B`
Mà `\hat{FBC}=60^o =>\triangleBFC` đều
`=>FC=FB=BC` (*)
Ta có: `F\in` trung trực `BH=>FH=FB` (**)
Từ (*)(**)`=>FH=FC=FB`
Xét `\triangleHFB`, có: `FH=FB=>\triangleHFB` cân tại `F`
Mà `\hat{HBF}=15^o =>\hat{HFB}=180^o -2\hat{HBF}=150^o`
Ta có: `\hat{HFC} + \hat{HFB} + \hat{BFC} = 360^o`
`=>\hat{HFC}=360^o - 150^o - 60^o`
`=>\hat{HFC}=\hat{HFB}=150^o`
Xét `\triangleHFC` và `\triangleHFB`:
`HF` chung
`FC=FB`
`\hat{HFC}=\hat{HFB}`
`=>\triangleHFC=\hat{HFB}(c.g.c)`
`=>\hat{FHC}=\hat{FHB}`
`=>\hat{BHC}=2\hat{FHB}=2\hat{FBH}=30^o`
`=>\hat{BHC}=30^o`
my hobby is collecting comics. I started my hobby 2 years ago. My mother took me to the bookstore and bought some comics for me.I like reading comics for me. I like reading comics in my freetime because it helps me relax. I spend all lucky money to buy comics. I find this hobby interesting because comics make me funny and excited.
I hope that in the future, i'll have a big bookshelf of comics to read them.
Hơi ngắn, xin lỗi nhé !
I have many hobbies, but I like reading most. Books are always a good friend to me. It is a good way to improve my vocabularies by exposing many new words.I star to reading book when i in grade 3.my brother inspired me to do that.I usualy share my hobby with my friend and my english teacher.By reading, I get better at concentration because it requires me to focus on what I am reading for long periods. It also opens up the knowledge door for me. Reading books tell me about the world's history, let me see the structure of the brain, or bring me a story of Sherlock Holmes. I think reading is one of the most interesting indoors activity and I will keep this hobby forever.
____Do________ you (get) ___get__________ up late this morning?
Hoang (not come) ________didn't come___________ home late yesterday evening.
What ___did__________ you (have)___have__________ for lunch yesterday?
Where _______did______ Nam (go) ______go_______ last summer?
Liz (help) ______helped_______ me a lot with my housework last week.
He (buy) ________bought___________ me some flowers last night.
I (get) __________got_________ a terrible headache last night.
He (knew) ________knew___________ him long time ago.
We (eat) _______will eat____________ some fish for dinner tomorrow.
My friends (travel) ______will travel_________ to Da Nang next week.
Last night, we (not watch) ______didn't watch_______________ TV.
My teacher (return) _______have returned______________ here soon
He (teach) ________taught_____________ us last year.
Her father (take) _____takes__________ her daughter to the dentist.
Mai (make) ______made_______________ a big cake yesterday.
There (be) _______has been______________ a storm here soon.
She (drink) _________drank____________ a lot of beer last night.
My mother (cook) _______will cook______________ dinner tonight.
Hai (not arrive) ___________hasn't arived__________ here soon.
______Are_________ you (give) _____giving__________ her a present?
Loan (help) ________helped__________ me do housework yesterday.
I (not have) ________didn't have_____________ any close friends last year.
They (not obey) _______didn't obey___________ their teacher last time.
____Did_______ you (get) ___get__________ up late this morning? (this morning -> QKĐ)
My teacher (return) _____will return______________ here soon
There (be) ______will be___________ a storm here soon.
Hai (not arrive) _________will arrive_____ here soon. (soon là dấu hiệu của thì tương lai mà a :v)
______Do______ you (give) ___give_____ her a present? (tự dưng chia HTTD làm j .-.
Sự phân bố dân cư :
- Dân cư Bắc Mỹ phân bố không đồng đều giửa phía tây và phía đông, miền bắc và miền nam.
- Mật độ dân số thấp nhất là phía bắc Canada và bán đảo A-la-xca dưới 1 người/km2 kế đó là miền núi Coóc-đi-e Hoa Kỳ.
- Mật độ dân số cao nhất là vùng đông bắc Hoa Kỳ: từ dải đất phía nam Hồ Lớn đến duyên hải Đại Tây Dương. Mật độ dân số trên 100 người/km2
- ¾ dân số Bắc Mỹ sống ở thành thị.
- Trong các năm gần đây, phân bố dân cư Bắc Mỹ có sự thay đổi nhất là trên lãnh thổ Hoa Kỳ, có sự chuyển dịch dân cư trên lãnh thổ Hoa Kỳ từ các vùng công nghiệp phía nam Hồ Lớn và Đông Bắc ven Đại Tây Dương hướng về phía nam và vùng duyên hải phía tây ven Thái Bình Dương do sự phát triển mạnh các ngành công nghiệp mới.
Question 1. Look! He ________ football now.
A. is playing B. plays C. played D. was playing
Question 2. It’s very ________ of you to help me.
A. talkative B. active C. nice D. confident
Question 3. Nam and Ba ________ ice cream at the moment.
A. eating B. is eating C. was eating D. are eating
Question 4. Steve can deal with difficult exercises. He’s a __________ boy.
A. creative B. intelligent C. sporty D. kind
Question 5. Please be ___________ when you have to use fire to cook.
A. handsome B. clever C. careful D. reliable
Question 6. She is so ___________ that she doesn’t talk much to strangers.
A. reserved B. clever C. active D. smart
Question 7. The part between the head and the body is the _________.
A. leg B. neck C. knee D. shoulder
Question 8. My friend, Lan is a ________ student. She always finishes homework on time.
A. hard-working B. confident C. shy D. reliable
Question 9. What does your best friend look like?
A. He is funny B. He is kind C. He is clever D. He is handsome
Question 10. What’s your classmate like?
A. She’s patient B. She’s beautiful C. She’s tall D. She’s thin
Question 11. Peter __________ a straight nose and fair skin.
A. goes B. comes C. does D. has
Question 12. Would you like _________ to the hospital to visit my mother?
A. to go B. going C. go D. will go
Question 13. _______ you _______ an English class tomorrow?
A. Do – have B. Are – having C. Will – having D. Is – have
Question 14. That girl has yellow hair. She has _______ hair.
A. black B. wavy C. blonde D. curly
Question 15. We should brush our ____________ twice a day.
A. feet B. teeth C. hair D. toe
Choose the letter A, B, C or D to complete the sentences
Question 1. Look! He ________ football now.
A. is playing B. plays C. played D. was playing
Question 2. It’s very ________ of you to help me.
A. talkative B. active C. nice D. confident
Question 3. Nam and Ba ________ ice cream at the moment.
A. eating B. is eating C. was eating D. are eating
Question 4. Steve can deal with difficult exercises. He’s a __________ boy.
A. creative B. intelligent C. sporty D. kind
Question 5. Please be ___________ when you have to use fire to cook.
A. handsome B. clever C. careful D. reliable
Question 6. She is so ___________ that she doesn’t talk much to strangers.
A. reserved B. clever C. active D. smart
Question 7. The part between the head and the body is the _________.
A. leg B. neck C. knee D. shoulder
Question 8. My friend, Lan is a ________ student. She always finishes homework on time.
A. hard-working B. confident C. shy D. reliable
Question 9. What does your best friend look like?
A. He is funny B. He is kind C. He is clever D. He is handsome
Question 10. What’s your classmate like?
A. She’s patient B. She’s beautiful C. She’s tall D. She’s thin
Question 11. Peter __________ a straight nose and fair skin.
A. goes B. comes C. does D. has
Question 12. Would you like _________ to the hospital to visit my mother?
A. to go B. going C. go D. will go
Question 13. _______ you _______ an English class tomorrow?
A. Do – have B. Are – having C. Will – having D. Is – have
Question 14. That girl has yellow hair. She has _______ hair.
A. black B. wavy C. blonde D. curly
Question 15. We should brush our ____________ twice a day.
A. feet B. teeth C. hair D. toe
1. My brother and I don't like playing video games.
-> I don't like __playing video games and neither does my brother__
2. Drinking lots of water and fruit juices everyday is good for you
-> It's ____good for you to drink lots of water and fruit juices everyday___
3.Did Lan help her parents on the farm
-> Lan_____helped her parents on the farm, didn't she?___
4.Hoa and Minh will go to the zoo next week
-> Hoa will____go to the zoo next week and so does Minh___
5.Noone helped us do the math homework
->We did___the math homework by ourselves
6. Eating habits in Japan are different from France
-> Eating habits in France are not __the same as in Japan_
1 I don't likeplaying video games and neither does my brothe
2 It's good for you to drink lots of water and fruit juices everyday
3 Lanhelped her parents on the farm, didn't she?
4 Hoa willgo to the zoo next week and so does Minh
5 We didthe math homework by ourselves
6 Eating habits in France are not the same as in Japan
1. Mr Tung, our English teacher (never/ be)________is never____________ late for lessons.
2. He (often/ clean)_________often cleans___________ his bedroom at the weekend.
3. My sister (never/ help)_____________never helps_______ me with my homework.
4. I (sometimes/ be)__________am sometimes__________ bored in the Maths lessons.
5. We (rarely/ watch)___________rarely wath_________ football on TV.
6. Tony (never/ play)______never plays______________ computer games with me.
7. We (usually/ be)_________are usually___________ at the sports centre on Sunday.
8. The school bus (always/ arrive)_________always arrives___________ at half past eight.
C nha
c thì phải