水平井的摩擦阻力随井斜角的增大而增大。
参考答案:对
I feel dizzy, and I __________ got a fever. [ ]
A. am
B. was
C. have
D. be
Everyone knows that _______ is dangerous to play with fire, but _______ is difficult is to prevent children from playing with fire.
A.it, it
B.what, what
C.it, what
D.what, it