【单选题】Sometimes we _____ words from a sentence but the meaning of the sentence doesn't change. [ ]
【多选题】When we say “sentence variety ”, what can we vary?
【单选题】治疗阵发性室上性心动过速的首选药物是( )
【单选题】If a sentence expresses the main idea of the sentence, we call it_______.
【单选题】When we say that we can change the second word in the sentence 'The girl is waiting outside' with another word or phrase, we are talking about the______inside the sentence.
【单选题】安全投入是指对安全活动所作出的一切人力、物力和财力投入的总和,包括( )