单项选择题
A．It down fell B．It fell down C．Down fell it D．Fell it down
We arrived at the station () late, or we()the bus. A．to...
单项选择题We arrived at the station () late, or we()the bus.
A．too much; would catch B．a little too; had caught C．much too; would have caught D．too much; would have caught
We will not attack () we are attacked; if attacked, we ...
单项选择题We will not attack () we are attacked; if attacked, we will certainly counter-attack.
A．if B．when C．unless D．even if
"Do you hear someone knocking at the door" "Yes, I did...
单项选择题"Do you hear someone knocking at the door" "Yes, I did. I heard him () three times."
A．knocking B．knocked C．being knocking D．knock
