55 D

56 B

57 C

58 B

59 B

60 B

61 B

62 A

63 A

64 C

45 B

46 C

47 D

48 A

49 C

50 C

51 C

52 A

53 B

54 A

em đăng lại bài cho rõ ràng nha

Ngu

1 B

2 D

3 C

4 B

5 A

6 D

7 A

8 A

9 B

10 C

Ex2

11 D

12 C

13 A

14 B

15 D

16 C

17 A

18 C

19 B

20 A

A

A

A

A

B

D

C

D

D

A

55 C

56 A

57 A

58 A

59 B

60 B

61 C

62 D

63 D

64 B

45.C

46.A

47.D

48.D

49.B

50.C

51.D

52.A

53.B

54.B

45 C

46 A

47 D

48 D

49 B

50 C

51 D

52 A

53 B

54 B

1. If we divide the mass of a substance by its density, we obtain its volume

-> To..... obtain the volume of a substance, we can divide its mass by its density......

2. Time, mass, and length are the most important dundamental units

-> The.....most important fundamental units are time, mass, and length........

3. The basic concepts of the thermodynamics are easily understood in terms of experiments

-> With...... experiments, the basic concepts of thermodynamics can be easily understood.............

4. At atom is the smallest particle that can not be split up in a chemical actions

-> The......The smallest particle that cannot be split in chemical reactions is an atom............

5. In a liquid, the depth and the pressure are in direct proportion

->In a liquid..., the pressure is directly proportional to the depth....................

6. The emission of alpha and beta particles causes a change in the atom

-> A change........ in the atom is caused by the emission of alpha and beta particles...........

7. Each radioactive element has a fixed rate of decay called half-life

->The half-life.......is a fixed rate of decay for each radioactive element......................

8.Fast moving a particles could split the nucleus of an atom

->The nuclues....can be split by fast-moving alpha particles.............

9. Lightweight nuclei can be combined in to heavier nuclei

->Heavier nuclei........can be formed by combining lightweight nuclei............

10. Cadmium absorbs neutrons, so cadmium robs are inserted or removed to control reaction

-> As.......cadmium absorbs neutrons, cadmium rods are inserted or removed to control the reaction........................

45 C

46 A

47 B

48 A

49 D

50 B

51 D

52 B

53 D

54 B

1 B

2 B

3 A

4 A

5 B

6 D

7 C

Ex20:

Hi Rosa,
Greetings from Osaka! Hope this finds you all well. I suppose by now school (1) will have closed for Christmas and you (2) will be enjoying a rest. It's hard to believe that Tim's already 18 and that it's only a few months until he (3) will be leaving school for college.
My main news is that my brother, Joe, and his family (4) will be arriving next Friday as part of their big trip around the world. By the time they get here they (5) will have been going to California and New Zealand. No doubt Joe's children (6) will have been planning it all out for months! They (7) won't be spending all their time with me. Joe has to go to Tokyo on business, so I (8) will be keeping the rest of the family entertained while he's away. Then they (9) will all be going to Kyoto

Ex21:

10.Our science teacher never remembers to correct our homework!
=> Our science teacher is always forgetting to correct our homework!

11.I have an appointment to see the doctor at four o'clock.
=> I am seeing the doctor at four o'clock.

12.The 100-metre runner is about to break her world record!
=> The 100-metre runner is on the verge of breaking her world record!

13.I need three months to finish my assignment.
=> In three months, I will have finished my assignment.

14.The last time I failed a test was at primary school!
=> I haven't failed a test since primary school!

15.Oliver and William have arranged to visit the planetarium today.
=>Oliver and William are visiting the planetarium today