—You’d better ask Mr Wang for help when _______ problems.
—I see, but I’m not sure when _______ time.
A. you have； having B. having； he has
C. to have； he has D. to have； having
—Be careful! A car may hit you.
—Thank you! I _______ I _______ so close to the road.
A. didn’t know； am standing
B. don’t know； am standing
C. didn’t know； was standing
D. didn’t know； would stand
Don’t try to do everything at once. Take it a bit _______.
A. at times B. at that time
C. at all times D. at a time
—_______ they _______ the book _______ to the library yet?
—Yes, they have.
A. Have； returned； / B. Have； returned； back
C. Did； return； / D. Did； return； back
He _______ until it began to rain.
A. didn’t stop working B. didn’t stop to work
C. stopped to work D. stopped working
The old lady didn’t know _______ when the house caught fire.
A. how to do with it B. how to do
C. what to do D. what to do it
