电平
参考答案:
电路中任一点的功率P1和另一点的功率P2之比的对数。
从7名运动员中选出4名组成4×100米接力队,求满足下列条件的不同安排方案的种数,
(1)甲、乙二人都不跑中间两棒;
(2)甲、乙二人不都跑中间两棒。
Sally turned all of her pockets inside out only to find $ 1.87 _____ buy her daughter a present for Christmas.
A.with what to
B.with that she can
C.in which to
D.with which to