《清明上河图》是我国______朝的绘画作品。
A.唐
B.宋
C.元
D.明
参考答案:B
Maintenance activities include().
① making enhancements to software products
② developing a new software product
③ correcting problems
④ adapting products to new environments
A.①②
B.①③④
C.②③④
D.①②③④
Tell the children ______ there not to make so much noise.
A.play
B.played
C.playing
D.to play