试验反力装置中的反力架系统应具有（）倍的安全系数。
A.1.0
B.1.2
C.1.5
D.2.0
参考答案：B
回答问题1和问题2。
People wrote letters to get in touch. Nowadays email has ________the way people communicate. [ ]
A. conveyed
B. translated
C. transformed
D. exchanged
