13. is/want                  14 has just met/ is talking
15 did they go                  16 boils / freezes
17 are feeling/ stayed             18 work / started / finished
19 drives/ walked                  20 watches / listened
21 go/ played       22 go/ stayed
23 rains/ rained     24 talked / didn't talk
25 watched / didn't watch     26 were you doing
27 isn't / writing    28 read     29 cleaned
30 was learning   31 wasn't watching 
32 are these students going
33 is rising     34 were eating     35 was watching
36 watched    37 was     38 was reading     
39 have studied     40 learnt/ was doing 
41 hasn't finished     42 have already seen      43 saw
44 have read     45 have read       46 lived
47 have had     48 started      49 has teached
50 has been     51 have never watched / hasn't seen
52 rains      53 was talking      54 to show