选用压力表时主要以介质的压力、（）为根据。
A．液位
B．温度及性质
C．流量
D．流量及性质
参考答案：B
The old building was founded_________ .
A．in 1820s
B．in the 1820
C．in the1820s’
D．in the 1820s
He felt ________about what to do next. [ ]
A. frightened.
B. happy
C. surprised
D. puzzled
