根据句意用括号中动词的适当形式填空，使句子的意思完整、正确。
Would you like________ (live) in the zoo , Eddie?
If we do nothing, soon there may be none __________ (leave) ．
When autumn comes , tree leaves ___________(turn) brown．
I___________(watch) TV when someone knocked at the door．
Mr Green _______(teach) us English since he came to our school．