辊道上（）的辊子应用最广泛。
A.阶梯形
B.锥形
C.圆柱形
D.多辊环
参考答案：C
Fully ________ looking after three children at home, she no longer has time to enjoy the various activities in the club.
A．attached to
B．occupied in
C．contributed to
D．devoted to
延迟性溶血反应发生在输血后
A．1～6日
B．7～14日
C．15～23日
D．24～30日
E．31～60日
