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16 tháng 9 2018

"Why is not Hoa lazy?" là đúng.

27 tháng 12 2021

typical

27 tháng 12 2021

typical

7 tháng 12 2017

uk nhưng bài này ở đâu vậy

7 tháng 12 2017

Xin lỗi nhưng mik chưa hiểu ý bài này

15 tháng 8 2020

ko biết

15 tháng 8 2020

1.Yes,it is because pizza is delicious,blended by simple ingredients

2.Yes,it is because clean vegetables is good for health

3.No,it isn'y because vegetables is good and clean for health everyone

4.No,it isn't because vegetables is cheap for somebody

Tịks nhé!Học tôta!:))

14 tháng 8 2020

1. My school is bigger than Hoa.

2. She is lazy, but her brother is very lazier = lazy

3. Playing is more interesting than study = studying

4. Mary is the most beautiful of the twins

5. These exercises are not more difficult than those ones = this one

14 tháng 8 2020

1. Hoa -> Hoa's 

2. bỏ very

3. study -> studying

4. most -> more

5. Câu này sửa cả câu: These exercises are not as difficult as those ones.

26 tháng 5 2022

1. He will be good at dancing.

2. She isn't interested in watching football matches.

3. Why don't we plant trees around our houses to get shade and fresh air?

4. We put garbage buns in the schoolyard to prevent lazy students from throwing trash.

26 tháng 5 2022

He will be good at dancing

She is not interested in watching football matches

Why don't we plant trees around our houses to get shade and fresh air?

We should put garbage bins around the schoolyard to prevent lazy students from throwing trash 

13 tháng 4 2016

a) Gọi  theo thứ tự ∆1, ∆2, ∆3 là giá của các vectơ 

 cùng phương với  => ∆1 //∆3  ( hoặc ∆1 = ∆3 )   (1)

 cùng phương với  => ∆2 // ∆3 ( hoặc ∆2 = ∆3 )   (2)

Từ (1), (2) suy ra ∆// ∆2 ( hoặc ∆1 = ∆2 ), theo định nghĩa hai vectơ  cùng phương.

Vậy 

a) đúng.

b) Đúng.

13 tháng 4 2016

a) Đúng                                  b) Đúng

c) Hai vectơ   = ( 5; 3) và  = (3; 5) không cùng phương nên không thể đối nhau, do vậy câu c) sai

d) Đúng

1. She is lazy, so she can't pass the exam.-> If it ..................................................................................................................................................2. He smokes too much; that's why he can't get rid of his cough.--> If .......................................................................................................................................................3. Olga and Ivan weren't paying attention, so they didn't see the sign marking...
Đọc tiếp

1. She is lazy, so she can't pass the exam.

-> If it ..................................................................................................................................................

2. He smokes too much; that's why he can't get rid of his cough.

--> If .......................................................................................................................................................

3. Olga and Ivan weren't paying attention, so they didn't see the sign marking their exit from the highway.

--> If .......................................................................................................................................................

4. We put off our trip because the weather was terrible.

--> But for ..............................................................................................................................................

5. Sally doesn't know what she has to do for homework because she was absent from school on Friday.

-> If ......................................................................................................................................................

6. Martin failed his driving test last week because he was very nervous.

--> But for...................................................................................................................................

7. His father is sad now because he failed the examination again.

--> If he …………………………………………………………………..…………………………..

8. They had a terrible accident because they were too careless.

--> But for ……………….…………………………………………………………………………...

9. We could accuse him of having stolen our car because we had evidence.

--> Without …………………………………………………………………………….............….

10. I don’t know many people. I am lonely.

--> Were …………………………………………………………………………………………..

11. I hope it will rain soon. Otherwise, we will lack of water.

--> If it ……………………………………………………………………………………………...

12. She can't be employed because she doesn't have a college degree.

--> Were …………………………………………………..……………………………………….

13. Because of the attractive salary, I didn’t give up the job

--> Had it………………………………………………….………………………………………….

14. The heavy rain prevented us from getting there.

--> Without ……………………………………………..…………………………………………...

15. Fortunately, she arrived in time to save the boy.

--> If she ……………………………………….…………………………………………….......….

16. You had better have this car serviced .

--> If I …………………………………………………………………………………………….....

17. Give me the money or I will kill her.

--> Should …………………………………………………………………….………………………

0
13 tháng 4 2016

a) Nối BM

Ta có AM= AB.cosMAB

=> || = ||.cos()

Ta có:    =   ||.|| ( vì hai vectơ  cùng phương)

=>  =   ||.||.cosAMB.

nhưng  ||.||.cos() = .

Vậy   .

Với . = . lý luận tương tự.

b)   .

. = .

=>   + . = ( + )

=>   + . =  = 4R2