机车车辆在曲线上运行时产生的离心力,半径越小,速度越高,则离心力就()。
A、越大;
B、不变;
C、越小
参考答案:A
The cigarette end thrown away by a careless farmer ______ the big forest and brought us great loss.
A.brought in
B.resulted from
C.led to
D.led out
输血可传播的疾病是:
A.有脓B.无脓C.脓已成熟D.脓浅E.脓深