K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

MN đã giúp mk trong thời gian qua ! Mong mn giúp mk lần này nữa nhé ! Chắc mg bt đề rùi chứ !! Thanks mg nhì nha ! HGH (Human Growth Hormone) could be the favorite drug at the next athletic world championships, and we might never know it. It is a natural substancr produced by the human body, and it helps children’s bones and muscles to grow. Scientists are allowed to make the drug and it is also legal to take HGH in most countries. HGH is considered a wonder drug for children....
Đọc tiếp

MN đã giúp mk trong thời gian qua ! Mong mn giúp mk lần này nữa nhé ! Chắc mg bt đề rùi chứ !! Thanks mg nhì nha !

HGH (Human Growth Hormone) could be the favorite drug at the next athletic world championships, and we might never know it. It is a natural substancr produced by the human body, and it helps children’s bones and muscles to grow. Scientists are allowed to make the drug and it is also legal to take HGH in most countries. HGH is considered a wonder drug for children. It helps many children with growth problems every year.
However, some athletes are now taking the drug. HGH helps add muscle in adults and recent research by the World Anti-Doping Agency shows that HGH may improve the sportsman’s time by 5% when he takes part in short, fast races. Some athletes say that HGH surely makes them stronger. It also helps them to recover more quickly from injuries.

Although it is banned by most professional sports, HGH is almost impossible to test for. The drug is completely natural and it will only show in tests for around 24 hours after taking it. Testing is usually done only during competitions, but athletes use HGH during training, so it is very difficult to know who has used the drug. This makes it very attractive for some athletes. Scientists are developing a new test which will find the drug in the body for up to two weeks. But it isn’t going to be easy. Everybody has different levels of natural HGH in their body.
For this reason, scientists are warning athletes of the possible problems with the drug. Research shows that HGH increase the risk of cancer. But is this enough to stop athletes from taking it? Scientists don’t think so. Some athletes will do all they can to win, and worry about their health later.

1. Which of these statements is false ?
A. HGH is a natural substance.
B. HGH is needed to help bones and muscles grow.
C. HGH is used as medicine for children.
D. HGH is not allowed to be produced in many countries.
2. The second paragraph tells you that ____.
A. some athletes believe HGH can help them do better.
B. HGH is mainly taken by some scientists.
C. research shows that HGH is effective in 5% of athletes.
D. HGH doesn’t have any effect on performance.
3. Apart from making them stronger, why is talking HGH attractive for some athletes ?
A. Because it can be taken during a competition.
B. Because it is very difficult to test.
C. Because it is allowed to take it.
D. Because it works for 24 hours.
4. Scientists are afraid that ____.
A. some athletes will pay no attention to the dangers of using HGH.
B. there isn’t any risk of developing cancer as a result of taking HGH.
C. health problems caused by HGH will stop athletes from taking it.
D. athletes’ results are almost the same, so they want HGH to help them be the best.
5. The text is about
A. suggestions for new ways of detecting HGH.
B. HGH as a legal drug for sprinters.
C. the use of HGH in professional sports.
D. HGH as a drug in the treatment of adults.

0
29 tháng 3 2019

hi

10 tháng 9 2021

c d a c a c a c a d b a b d a

19 tháng 10 2021

The teacher always take me to real the difficult words.

19 tháng 10 2021

taught

Bài 2:

a: Ta có: \(5x\left(x-1\right)+10x-10=0\)

\(\Leftrightarrow\left(x-1\right)\left(5x+10\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-2\end{matrix}\right.\)

b: Ta có: \(\left(x+2\right)\left(x+3\right)-2x=6\)

\(\Leftrightarrow\left(x+2\right)\left(x+3\right)-2\left(x+3\right)=0\)

\(\Leftrightarrow x\left(x+3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-3\end{matrix}\right.\)

c: Ta có: \(\left(x-1\right)\left(x-2\right)-2=0\)

\(\Leftrightarrow x\left(x-3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=3\end{matrix}\right.\)

9 tháng 9 2021

\(1,\widehat{D}=360-\widehat{A}-\widehat{B}-\widehat{C}=360-120-50-90=100\)

\(2,\widehat{D}+\widehat{C}=360-\widehat{A}-\widehat{B}=360-50-110=200\\ \Rightarrow4\widehat{D}=200\Rightarrow\widehat{D}=50\Rightarrow\widehat{C}=50\cdot3=150\)

15 tháng 9 2021

=x^4+1+2x^2+3x^3+3x+2x^2

=x^4+3x^3+4x^2+3x+2x^2

=x^3+x^3+2x^3+2x^2+2x^2+2x+x+1

=x^4+3x^3+4x^2+3x+1

9 tháng 9 2021

\(3,\\ a,\dfrac{\left(1+\sqrt{x}\right)^2-4\sqrt{x}}{1-\sqrt{x}}\\ =\dfrac{\sqrt{x}-2\sqrt{x}+1}{1-\sqrt{x}}=\dfrac{\left(1-\sqrt{x}\right)^2}{1-\sqrt{x}}=1-\sqrt{x}=1-\sqrt{2}\)

\(b,\dfrac{\left(\sqrt{x}-\sqrt{y}\right)^2+4\sqrt{xy}}{1+\sqrt{xy}}\\ =\dfrac{x+2\sqrt{xy}+y}{1+\sqrt{xy}}=\dfrac{\left(\sqrt{x}+\sqrt{y}\right)^2}{1+\sqrt{xy}}\\ =\dfrac{\left(\sqrt{2}+\sqrt{3}\right)^2}{1+\sqrt{6}}=\dfrac{5+2\sqrt{6}}{1+\sqrt{6}}\\ =\dfrac{\left(5+2\sqrt{6}\right)\left(\sqrt{6}-1\right)}{5}\\ =\dfrac{3\sqrt{6}+7}{5}\)

26 tháng 3 2017

1.

1.2 +2.3 +...+97.98

=1/3.(1.2.3 +2.3.3 +3.4.3 +...+97.98.3)

=1/3.(1.2.3 - 0.1.2+ 2.3.4 -1.2.3 + 3.4.5 -2.3.4 + ... +97.98.99 -96.97.98)

=1/3 . 97.98.99

= 313698

=>1.2 +2.3 +...+97.98-x=16

=>313698-x=16

=> x=313682

4. 

\(\left[\left(\frac{36}{x}-x\right):x-x\right]:x-x=-x\)

\(\left[\left(\frac{36}{x}-x\right):x-x\right]:x=-x+x\)

\(\left[\left(\frac{36}{x}-x\right):x-x\right]:x=0\)

\(\left[\left(\frac{36}{x}-x\right):x-x\right]=0\)

\(\left(\frac{36}{x}-x\right):x=x\Rightarrow\frac{36}{x}-x=x^2\)

\(\frac{36}{x}=x^2+x=x\left(x+1\right)\Rightarrow36=x^2\left(x+1\right)\)

Mà Ư(36)={1;2;3;4;6;9;12;18;36}; 9 là số chính phương duy nhất bé hơn 36=> x2 = 9 => x=3

2 câu kia thì đợi một lúc.

6 tháng 7 2021

ok bạn

12 tháng 10 2021

OK BẠN