@Nguyễn Thị Huyền: Câu 1 của bạn chắc có sự nhầm lần trong đề, bạn xem lại nhé. Chứ nếu đề như này thì không thể giải được. :|

                                                                         giải

1 giờ có số em bé ra đời là:

        264x 60=15840(em bé)

1 ngày số em bé ra đời là:

15840x24=330 160(em bé)

1 tháng có số em bé ra đời là:

330 160x30=11 434800(em bé

1 năm có số em bé ra đời là :

11 434800x12=136857600(em bé)

vậy mỗi năm trên trái đất có 136857600 em bé ra đời

Hoc24 mới thay đổi chính sách gửi bài, theo đó, bạn phải chọn đúng chủ đề cho câu hỏi.

Vì gửi câu hỏi đúng chủ đề thì sẽ nhanh nhận được sự hỗ trợ của các bạn cũng như của giáo viên hoc24.

Nick nào mới vậy bạn?

Hoc24 có tích hợp với trang doc24.vn. Có thể bạn đã đăng ký 1 nick mới trên doc24?

Hai con lắc lò xo có cùng độ cứng k. Biết chu kỳ dao động T₁ = 2T₂. Khối lượng của hai con lắc liên hệ với nhau theo công thức

A. m2= 2 m1

B. m₂ = 4m₁.

C.  m₁ = 4m₂.

D. m₁ = 2m₂

Câu 2: Will you please speak louder? I _________hear you.

A. mustn't B. needn't C. can't D. shouldn't

Câu 3: Candidates _________ bring books into the examination room.

A. shouldn't B. won't C. mustn't D. needn't

Câu 4: Taking soup is easy and fast; just put it in your mouth and_________

A. digest B. taste C. swallow D. chew

Choose the underlined part that needs correcting in each of the following sentences, from 5 to 9

Câu 5: The new school (A) will be open (B) soon by (C) the local government (D)

Câu 6: All the homework (A) must been (B) done (C) before we go to (D) school.

Câu 7: The plants (A) should (B) be (C) water (D) every day.

Câu 8: Be careful (A) of that dog! (B) It need (C) bite (D) you.

Câu 9: Peter is driving (A) fast (B) , he can (C) be in (D) a hurry.

Câu 10: Mai: Do you have any plan for the weekend?

Lan: I haven't decided yet. I _________ go to the countryside to visit my grandparents.

A. will B. may C. can D. must

Câu 11: _________ is the natural environment in which a plan or an animal lives.

A. habitant B. habit C. inhabitant D. Habitat

Choose the word whose underlined part is pronounced differently from the rest in each group, from 12 to 14

Câu 12: A. faced B. mended C. waited D. invited

Câu 13: A. resort B. visit C. forest D. reason

Câu 14: A. natural B. nation C. nature D. native

Câu 15: It's a serious problem. I don't know how it _________

A. can solve B. can be solved C. could be solved D. could solve

Câu 16: Different conservation efforts have been made in order to save _________ species

A. endanger B. endangered C. danger D. dangerous

Câu 17: We ______ drive fast; we have plenty of time.

A. needn't B. mustn't C. must D. need

Câu 18: Endangered species are plant and animal species which are in danger of _________

A. exist B. extinction C. extinct D. existence

Câu 19: Leave early so that you ______ miss the bus.

A. shouldn't B. didn't C. won't D. mustn't

Câu 20: If I didn't do my job properly, I _________

A. will sack B. would be sacked C. would sack D. will be sacked

S + be + always + V-ing: thể hiện ý than phiền, phàn nàn 

Đáp án: 

The baby is always throwing his food onto the floor and making his mother 

Hoa, Nga and her cousin Nhi were bored, so Nga suggested that they play a game called 20 Questions. She explained the rules and then the girls started to play. Nga thought of a place and she gave the others a clue by saying that it wasn't in Viet Nam. Nhi found out the place was in New York. Hoa thought that it was the Golden Gate Bridge, but that is in San Francisco. Nhi was right when she said it was the Statue of Liberty.

1. He wrote that story in 1900.

→ That story was written in 1900 by him.

2. Someone has already asked him to do it.

→ He has been asked to do it.

3. Should you ease the pain with ice and cold water?

→ Should the pain be eased with ice and cold water?

4. He hurt his leg in an accident.

→ His leg was hurt in an accident

5. Did your brother lend me this book?

→ Was this book lent me by your brother?

1. My parents have worked in this factory for over 20 years.

-> Over 20 year ago, my parents began to work in this factory.

-> Over 20 year ago, my parents began working in this factory.

2. He has worked at the factory for 15 years.

-> He started working at the factory 15 years ago.

-> He started to work at the factory 15 years ago.

3. We have learned English for one year .

-> We began to learn English one year ago.

-> We began learning English one year ago.

4.How long is it since they bought the house?

-> When did they buy the house?

5. When did you last see Tom?

-> How long haven't you seen Tom?