AFTN电报最长可发（）个字符。
A、3800
B、3200
C、2100
D、1800
参考答案：C
—What _____ did you do?
—I hung out with my friend and took some photos.
A. else
B. other
C. more
D. any
弹性体和塑性体改性沥青防水卷材不透水性试验所需要时间是（）min。
A.30
B.60
C.100
D.120
