下列不属于经纬仪的仪器构成的是
A. 水准器
B. 基座
C. 水平度盘
D. 三脚架
经纬仪是测量()的仪器
A. 水平角
B. 竖直角
C. 可以间接测量高差
D. 身高
I tried to _________them down to their promise, but I failed.
A. ask
B. tell
C. nail
D. knock
Nobody but Jack and Tom ________ in the office yesterday.
A. are
B. was
C. were
D. have been