这些英语单项选择题,老师该讲错了吧?还有相应知识点附上,

这些英语单项选择题,老师该讲错了吧?还有相应知识点附上,
We're going to the bookstore.You can go there with us__you can meet us there later.
A.and B.but C.or D.then
milk quickly turns sour__it's in a fridge.because it is very hot today.
A.until B.since C.unless D.though
He asked me__.
A.if she will come B.how many books i want to have C.they would help us do it D.what was wrong with me