存查煤样的保存时间不少于（）个月。
A、1
B、2
C、3
参考答案：C
1.996精确到0.01的近似数是[ ]
A.2
B.2.0
C.1.99
D.2.00
Carl wanted to play a joke on Bob but gave himself _____ by laughing.
A．away
B．in
C．out
D．up
