He is at school. He ____________ at home. [ ]
A. is
B. isn't
C. not is
D. think
答案:B
下列不属于热电阻温度计的是()温度计。
A.铂电阻
B.铜电阻
C.铂电偶
D.半导体热敏电阻
自交系配合力的测定方法有()、()、()等。