题目

下列说法中正确的是（ ） A . 两条不相交的直线是平行线 B . 一条直线的平行线有且只有一条 C . 在同一平面内，若a∥b，a∥c，则b∥c D . 若两条线段不相交，则它们互相平行 答案：C1用所给动词的适当形式填空。 1.Let me _________ (help) you with your English. 2.-- Where is your mother?  -- She _________ (ride) a bike. 3.He with his friends often ___________ (fly) kites on Sundays. 4.His parents often ask him___________ (not watch) TV after 9p.m. 5.Thank you for __________( invite ) us to your party.