【简答题】It depends whether it is going to rain.
【单选题】It is going to rain. We ride _______. [ ]
【单选题】Global warming is a real problem.
【单选题】Why global warming is a big threat for human?
【单选题】Please lock the door;______, bring the umbrella to me. It looks as if it is going to rain.
【单选题】Time flies by. 属于哪种句子主干类型