300m=0,3km

$a,A=9=3^3$

$b,B=1089={11}^2.3^2={33}^2$

$c,C=110889=9^2\times x{37}^2={333}^2$

do you help your mother to do the laundry?

${64}^7={\left(2^6\right)}^7=2^{42}$

$4^3={\left(2^2\right)}^3=2^6$

${81}^{12}={\left(3^4\right)}^{12}=3^{48}$

$3^5=3\cdot 3\cdot 3\cdot 3\cdot 3=243$

${125}^{30}={\left(5^3\right)}^{30}=5^{90}$

${25}^{12}={\left(5^2\right)}^{12}=5^{24}$

famous

I spend about 2 hours each day doing my homework

3  Can I order a cheese and meat pizza please?

4 Can you spell that please?

5 West lake is the largest lake in HN

6 The highest mountain in the world is Mount Everest

7 We must arrive on time

8 What else do you know

9 The Himalaya is a range mountain

10 It look incredible

IV

1 clevener => clevenest

2 don't => doesn't

3 play => playing

4 go => will go

5 short => shorter

6 bigger => biggest

7 among => between

8 live => lives

9 visit => to visit

10 to take -> take

-Have a headache, stomachache, sore throat, fever, backache, temperature, flu

-Have spots, cough

-Feel dizzy, sick, weak, tired,

Câu 85 : Đáp án B vì trong phân tử có nhóm chức $OH$

Câu 86 : D

Câu 87 : C

Câu 89 : Đáp án D (1,2,4,5)

Câu 90 : Đáp án B