CHo \(A=\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{2020^2}\) chứng tỏ A<1

Muốn có 10 lít nước ở \(40^oC\) thì phải đổ bao nhiêu nước đang sôi vào bao nhiêu lít nước ở \(20^oC\) . Lấy nhiệt dung riêng của nước là \(\dfrac{4200J}{kg}.K\)

I. Rewrite sentences, using "I wish..........."

1. I don't know many English words.

I wish ..............................................................................

2. My friend can not stay with me longer.

I wish .............................................................................

3. I don't have time to go around the city.

I wish.............................................................................

4. We don't have a computer therefore we cannot get access to the Internet.

I wish ............................................................................

5. I can not go to the car show at the city show ground

I wish............................................................................