Bài 2 
c1: enjoyed
C2: has taught

I.
1.goes
2.brushes
3.plays
4.am trying
5.will have
6.is running
7.are
8.drinks...drinks
9.does
10.will the next train leave / does the next train leave
11.is boiling
12.goes
13.are you doing...am preparing
14.goes...eats
15.covers
II.
1.enjoyed
2.has taught
3.did you spend
4.have already finished
5.has worked
6.has lived
7.have just buy
8.Have you ever been
9.was...did not go

I/
1, goes
2, brushes
3, plays
4, am trying
5, are having
6, is running
7, are
8, drinks - drinks
9, does
10, does the next train leave?
11, is boiling
12, goes
13, are you doing - am preparing
14, goes - eats out
15, covers
II/
1, enjoyed
2, has tought
3, did you spend
4, have already finished
5, has worked
6, has lived
7, have just bought
8, have you even been.....
9, was - didn't go