几题英语选择题，解释下为什么

①if they lived in a cold climate they_____shoes.a.would be having to wear....b.could be wearing....c.would need to wear.....d.would not need to wear....从句是过去时，主句要过去将来时，

答案是 c 
②how much we_____going on a cycling holiday.a.will be enjoyong....b.could enjoy...c.enjoy....d.would enjoy...

答案是a
③i wish you ___ me about your plans yesterday.a.have told ....b.told ....c.had told ....d.would tell

答案是c     与过去情况相反的 虚拟语气
④the___distance between the two cities is about 300 miles.a.continuous....b.constant....c.contact....d.contrast....

答案是b  不变的  两个城市之间的 恒定距离大约是300 英里

⑤she was____to stay the night, although she knew she shouldn't.a.suggested....b.convinced....c.persuaded....d.decided..

答案是c .
⑥tom,jack and john help____to finish the project.a.one another....b.each other.....c.each and other....d.one and other...

答案是 a