船政十三厂现存的为()。
A、铁胁厂;
B、钟表厂;
C、锅炉厂;
D、轮机厂
参考答案:D
I have never heard a worse voice than hers. She is ________ but a good singer.
A.something
B.everything
C.nothing
D.anything
测量结果与被测量真值之间的差是()。
A.偏差
B.系统误差
C.测量误差
D.随机误差