题目

A few years after the card was made,the Postage Act was passed in the UK, _____it possible to send letters for a penny.    A. make    B.made     C.to make    D.making 答案：D已知，，，是空间四点，命题甲：，，，四点不共面，命题乙：直线和不相交，则甲是乙成立的（  ）A．充分不必要条件B．必要不充分条件C．充要条件D．既不充分也不必要条件