比1小2的数是( )
A.-3
B.-1
C.1
D.3
答案:B
∵1-2=-1,∴比1小2的数是-1.故选B.
Max is Chinese. He ________ to practice Chinese more.
A.needn’t
B.don’t need
C.doesn’t need
D.needs not
淬火加高温回火的热处理的称为:()
A.退火
B.正火
C.调质
D.消氢处理