Choose the word or phrase that best fits the blank space in each sentence:

1.She’s worried_______the result of her final exam.
A. in B. on C. at D. about
2.You should have the_______check the pipes in your house.
A. doctor B. mechanic C. plumber D. electrician
3.I think we should turn on the lights. - _______.
A. OK B. All right C. That’s a good idea D. All are correct
4.How about_______by bike instead of motorbikes?
A. to travel B. travel C. traveling D. traveled
5.Hung is sick. _______, he can’t go to school.
A. Therefore B. And C. But D. Because
6.If we_______talking, we’ll be punished.
A. look after B. go on C. turn on D. account for
7.Each item has its own_______.
A. label B. name C. thing D. resource
8.We_______solar panels on the roof of our house to receive the energy from the sun.
A. keep B. install C. label D. innovate
9.Let’s save natural_______by using solar energy.
A. label B. name C. thing D. resources
10.Please turn_______the air conditioner. It’s so hot!
A. off B. in C. on D. into

Rewrite the sentences so that they are nearest in meaning to the sen tence printed before them.

1. Speak English in slass regularly.

-> I suggest ..........................

2. He attends the course. He needs to improve his writing.

-> Because ..........................

3. Why don't we plant some roses in the garden.

-> I think ...........................................

4. I'm a doctoe, and so is Thuy.

-> Thuy ...................................

tìm nghiệm nguyên của phương trình:

x⁴+x³+x²+x=y²+y

Tìm \(\overline{ab}\) sao cho \(\dfrac{ab}{|a-b|}\) nguyên tố.

Cho n\(\in\)N (n\(\ge\)2) và p nguyên tố thỏa mãn: (p-1)\(⋮\)n và (n³-1)\(⋮\)p. Chứng minh: n+p chính phương.

Tìm x,y \(\in\)N để : 1+\(\sqrt{x+y+3}\)=\(\sqrt{x}+\sqrt{y}\).

giải hpt:

\(\left\{{}\begin{matrix}2x+2y+xy=5\\27\left(x+y\right)+y^3+7=26x^3+27x^2+9x\end{matrix}\right.\)

giải hpt:

\(\left\{{}\begin{matrix}x+\dfrac{1}{x}+y-\dfrac{1}{y}=3\\x^2+\dfrac{1}{x^2}+y^2+\dfrac{1}{y^2}=5\end{matrix}\right.\)

gpt:

1, 3\(\sqrt{3}\)(x²+4x+2)−\(\sqrt{x+8}\)=0