Con người không thể thiếu oxy, vì oxy là nguyên liệu cho mọi tế bào con người hoạt động. 
Rừng cây cũng có sự trao đổi khí hàng ngày, nên ví rừng cây là một lá phổi. 
Rừng cây trao đổi khí, nhưng trao đổi kiểu tạo ra thêm oxy cho con người sử dụng, nên rừng cây gọi là lá phổi của con người. 
Và lá cây thì có màu xanh, nên gọi là LÁ PHỔI XANH CỦA CON NGƯỜI.

2-\(\frac{3}{8}+\frac{1}{4}=\frac{16}{8}-\frac{3}{8}+\frac{2}{8}=\frac{15}{8}\)

1. Lan is (intelligent) ....more intelligent........ Hoa in the first semester.

2. I'm tired. I'd like (sit) ......to sit....... down.

3. Is Mai (eat) ....eating....... a bowl of noodles at the moment?

4. That is (heavy) .....the heaviest....... traffic I have ever seen!

5. My mother could (play) ...play........... piano when she was 6 years old.

6. Shall we (turn) ....turned........ off the light to save electricity when nobody is in the room.

7. We (pass) ....will pass......... If we studdy harder.

8. Da Nang is (fame) ......famous....... for the beaches.

1. I / hungry / thirsty => I am hungry and thirty

2. How many / books / there /table? => How many books are there in the table ?

3. These / your notebooks? => Are these your notebooks ?

It was Teacher’s Day last month. We held a lot of celebrations in the park near our shool. There were many teachers and students. We danced beautifully and sang many favourite songs. Some students told funny stories about pets. Some played exciting games. Everyone enjoyed the celebrations a lot.

1. When did they hold the celebrations?.........They held the celebrations last month..............................................................................................................

2. Where did they hold the celebrations?........In a park..............................................................................................................

3. Who was there?...............There were many teachers and students.......................................................................................................................................

4. What did the students do?.......... They danced beautifully and sang many favourite songs. Some students told funny stories about pets. Some played exciting games...............................................................................................................................

5. Did everyone enjoy the celebrations?..........Yes , they did.....................................................................................................

Alice: There ............were ........................... a Music Festival at my last week.

Tom: How many people ...................were.................... there at the festival?

Alice: There are a lot of .......people................................

calendar:        lịch                                                                   atlas: bản đồ

biology:            môn sinh học                                              household:liên quan đến nhà

deligthful:         vui sướng                                                           concert: buổi hòa nhạc

except:                       chấp nhận                                       material: tài liệu

snack:bim bim . đồ ăn nhẹ

blindman's bluff: trốn tìm

enegertic: năng lượng , 

số sách tham khảo là 

\(1365-\frac{1}{3}.1365=910\)cuốn sách

ĐS: 910 cuốn sách

9 giờ = 8 giờ 60 phút

thời gian người đó đi xe máy trên quãng đường là:

8 giờ 60 phút - 7 giờ 15 phút - 15 phút = 1 giờ 30 phút

1 giờ 30 phút = 1,5 giờ

quãng đường người đó đi dài là:

32 x 1,5 = 48 (km)

đáp số; 48 km.

1 She last ate this kind of food in January

She hasn't eaten this kind of food since January

2 Walking in the rain gives my brother pleasure.

My brother enjoys walking in the rain

3 Have you ever played a computer game before?

Is this the first time you have ever played a computer game?

4 The front yard is too small to play soccer in.

The front yard isn't big enough for us to play soccer

5 " Don't stay up too late"My sister said

My sister asked not to stay up too late

6 It's 4 years since I last spoke to her 

I haven't spoken to her for 4 years

7 No one in our school is as intelligent as Mai is 

Mai is the most intelligent girl in our school

8 He'd rather play golf than tennis

He prefers playing golf to playing tennis

9 Your younger brother is too weak to lift that box

Your brother is not  strong enough to lift that box

10 Hung'hobby is collecting stamps

Hung is interested in collecting stamps