(2013湖南娄底)—Always look around________you cross the street，David．
—OK．I know，Mum．
A．until
B．before
C．unless
The thieves ran away at once when the burglar alarm(防盗报警器)________．
A．went away
B．went out
C．went off
D．went through
(2013甘肃兰州)I overslept this morning．By the time I got to the train station，the train________(leave)．
—Did you see Mr Smith when you were in France?
—No．When I________France，he________to China．
A．had arrived in；had gone
B．arrived in；has been
C．got to；had gone
D．had got to；had been
He told us that he________the letters in the morning．
A．will post
B．have posted
C．was posting
D．had posted
By nine o’clock yesterday evening，we________our work．
A．have finished
B．finished
C．had finished
D．finish
