II,

1. more interesting

2. well

3. fewer

4. worst/ more comfortable

5. more supertitious

6. busiest/ busier

7. narrower

8. hotter/ hottest

III,

1. We can enable girls to enrol in this school.

→Girls can be enabled to enrol in this school.

2 Parnts should encourage children to play sports.

→Children should be encouraged to play sport.

3. You mustn't force kids to do what they don't want.

→Kids mustn't be forced to do what they don't want.

4. Government must eliminate hunger and poverty. 

→Hunger and poverty must be eliminated by government.

5. They may demolish this building in the future.

→This building may be demolished in the future.

IV,

1. An interactive whiteboard is an electronic device. It helps students learn English in a more stimulating way.

→An interactive whiteboard is an electronic device which helps students learn English in more stimulating way.

2. People may suffer from chronic headaches. Their work involves using a computer for most of the day.

→People whose work involves using a computer for most of the day may suffer from chronic headaches.

3. Electronic dictionaries are now common. They can be very easily downloaded into your personal electronic devices.

→Electronic dictionaries which can be very easily downloaded into your personal electronic devices are now common.

4. Students have a smartphone. They may spend many hours reading and watching, and forget about their learning.

→Students who may spend many hours reading and watching, and forget about their learning have a smartphone.

5.Smartphones, laptops and tablets are the moderm devices. They have changed the way we think.

→Smartphones, laptops and tablets are the moderm devices which have changed the way we think.

Bài 2. 2.well.
3.fewer
4.bad/ comfortable
Bài 3. 2.Children should be encouraged to play sports by parents.

3. Kids hadn't to be forced to do what they don't want.
4. Hunger and poverty had to be eliminated by the goverment.