下列说法中，正确的个数有（　　）

①在同一平面内不相交的两条线段必平行

②在同一平面内不相交的两条直线必平行

③在同一平面内不平行的两条线段必相交

④在同一平面内不平行的两条直线必相交

把陈述句换成把字句

①司马懿的十万魏兵被诸葛亮的空城计吓退了。②在最后关头，敌人的碉堡被董存瑞舍身炸掉了。

用方框中所给单词的适当形式填空，使短文通顺、正确、连贯（每个单词限用一次）。                                  

get,  look,  some,  year,  a,  write,  by,  tomorrow,  work,  other

      Tommy is a schoolboy. He's thirteen ____  old. He's in Class 3, Grade 1. He always____  up early and he often goes to school ____ bike. He likes English, Chinese and some ____ subjects. He enjoys singing and dancing. But now he is having ____ English class.____ ! some of the students are reading books and some of the students are____  the new words. They are ____  hard . But ____  is Saturday. They don't have ____ classes. He and his friends will go to the movies. I think they'll have fun.

下列条件与有序实数对不能构成一一对应的是（　　）

甲、乙两人从赤道出发，甲向北行，乙向东行，若两人前进方向各自保持不变。则(  )