Lily _____________ well in English. [ ]
A. don't do
B. doesn't do
C. isn't do
D. do
答案:B
斜坡上丈量距离时,可以采用平拉法,亦可以沿坡面取()再进行改正以求得平距。
A.平距
B.距离
C.垂距
D.斜距