I.

good -> well

bad -> badly

slow -> slowly

quick -> quickly

skillful -> skillfully

clear -> clearly

safe -> safely

sudden -> suddenly

careless -> carelessly

recent -> recently

free -> freely

strict -> strictly

II.

1. in

2. for

3. to / on

4. to

5. of

1. on

2. of

3. to

4. on

5. in

Nước ở dòng sông này thì sạch hơn

1. to meet

2. for

3. are doing

4. weight

5. well

Spend ...V_ing

speaking -> to speak

little -> few

to smoke -> smoking

get -> getting

as -> because