A:3+5
B:3+52
C:1+5
D:1+52
将下列句子改为陈述句。
①有了危险难道不应该让别人先出去吗?
②他们怎么可能买到很多很好的礼物呢?
There was a time ______ I thought my dad didn't know a thing about being a good father.
a,b是同一平面内不重合的两条直线,则直线a与直线b的位置关系是( )