千分尺属于()。
A.特殊量具;
B.标准量具;
C.微分量具;
D.游标量具。
参考答案:C
The money they have raised is used ______ the poor children in our class . [ ]
A. to helping
B. help
C. helpful
D. to help
当指挥信号不明时,可凭经验仔细操作。