________important memory is！We cannot work well without it.
A.How B.What a C.What D.What an
Li Na succeeded in ________ a Grand Slam singles title（大满贯单打冠军）On 5th June，2011.
A.win B.to win C.winning D.to winning
—Have you finished painting the fence, Elsa?
—No. I forget ________ it.
A.paint B.to paint C.painting D.painted
To save water, the parents told their children ________ their teeth under a running tap.
A.to brush B.not brushing
C.not to brush D.brushing
Every night, Tom sleeps ________the window open.
A.with B.for C.to D.in
I didn't pick up Lucy at the airport. she _ by the time I arrived.
A. has left B. will leave C. left D. had left
