Tìm lỗi sai và sửa lại:

1. Doesn't Nam's mother go always to work by bus? -> always go

2. Eating too many candies cause decay. -> causes

3. Million of forgein visitors come to Vietnam every year on their holiday. -> Millions

4. Some young people are working like hospital volunteers. -> as

5. The teacher, together with his students, are planting trees. -> is

Cho dạng đúng của từ trong ngoặc:

1. We seldom (eat) .....eat..... before 6:30

2. Look! A man (run) .....is running..... after the train. He (want) wants to catch it.

3. I (do) .......am doing..... an exercise on the present tenses at this moment and I (think) ....think.... that I (know) ....know.... how to use it now.

4. You ( watch).....Did you watch.....TV last night?

5. Miss Helen (help) ......will help..... you as soon as she (finish) ......finishes...... that letter tomorrow.

6. We ( know).......will know...... the result of the exam in 3 weeks.

Tìm từ có phát âm khác với những từ còn lại:

1. A. horrible B. hour C. house D. here

2. A. through B. author C. clothes D. thumb

3. A. marbles B. classes C. teaches D. changes

4. A. new B. sew C. few D. knew

5. A. enjoyed B. preferred C. listened D. decided

A = \(\dfrac{2}{1\times2}+\dfrac{2}{2\times3}+...+\dfrac{2}{98\times99}+\dfrac{2}{99\times100}\)

A = \(2\left(\dfrac{1}{1\times2}+\dfrac{1}{2\times3}+...+\dfrac{1}{98\times99}+\dfrac{1}{99\times100}\right)\)

= \(2\left(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{98}-\dfrac{1}{99}+\dfrac{1}{99}-\dfrac{1}{100}\right)\)

= \(2\left(1-\dfrac{1}{100}\right)\)

= \(2\times\dfrac{99}{100}=\dfrac{99}{50}\)

3“Me? No, I didn’t take Sue’s calculator” Said Bob.-> Bob denied ..taking Sue's calculator...
5“ I must see the manager.” he cried. -> He insisted ...on seeing the manager...
6“ If you wanted to take my bike, you should have asked me first” said Mike to his brother.
-> Mike criticized ..his brother for taking his bike without asking him first..
8“ It was kind of you to help me with my homework” Lan said to Hoa. -> Lan thanked ...Hoa for helping her with her homework...
9“ Shall we walk there? It’s not far,” he said. -> He proposed .....walking there.....
10“ turn off the computer. You are not allowed to play game now,” Dick mother said.-> Dick’s mother prevented .....him from playing games......
11“ I’m sorry that I broke the glass,” said Peter. ( apologized) -> Peter ...apologized for breaking the glass...
12“ You should have waited for us,” the team leader said to John. ( criticized)

-> The leader criticized John for not waiting for them.
13“ Let’s invite Mr. Brown to the party next weekend” he said. ( suggested)

-> He suggested inviting Mr. Brown to the party the following weekend.
14“ You stole the jewels” the inspector said to him.( accused)

-> The inspector accused him of stealing the jewels.
15“ I only borrowed your car for some hours” the man said. (admitted)

-> The man admitted borrowing his car for some hours.
16“ I’m sorry I damaged your tape recorder, Mike.” Said Bob.-> Bob apologized ...Mike for damaging his tape recorder...
17“ You damaged my camera’ said Jane to Henry. -> Jane accused ..Henry of damaging her camera...

a) ta co : 9^12 = 3^24 = 27^8

vi 8>7 suy ra 9^12>37^7

b) ta co : 3^500 = 243^100;7^300 = 343^100

vi 243<343 suy ra 3^500<7^300

c) ta co : (1/32)^10 = (1/2)^50;(1/4)^24 = (1/2)^48

vi 50>48 suy ra (1/32)^10>(1/4)^24

Đun nóng m gam hỗn hợp gồm 2 este của cùng một axit và 2 ancol đơn chức kế tiếp nhau trong dãy đồng đẳng trong dung dịch KOH (vừa đủ) thu được m gam muối. Vậy công thức của 2 ancol là

A. C3H7OH và C4H9OH

B. C3H5OH và C4H7OH

C. C2H5OH và C3H7OH

D. CH3OH và C2H5OH