1) walks
2) is
3) doesn't work
4) Do you often speak
5) is answering questions
6) stays
7) do not often get
8) get
9) are they discussing now
10) are
11) do they know
12) will revise; will do
13) Are they revising
14) is he doing; is
15) is he doing; is translating
1) walks
2) is
3) doesn't work
4) Do you often speak
5) is answering questions
6) stays
7) do not often get
8) get
9) are they discussing now
10) are
11) do they know
12) will revise; will do
13) Are they revising
14) is he doing; is
15) is he doing; is translating