Since we have it, the construction have subject and verb, so it becomes a main clause. so if there is no parenthesis, we could not add comma. And also it becomes "A and B" not "A, B, and C"
it here make the clause to be a main clause, so the comma before the and should be dismissed;and the word 'merged' should have a counterpart in a past tense, apparently 'was begun' is not the ideal counterpart
太wordy it is是主句的话communication后面不能加, begun没必要被动
not...but..是并列结构,前面已经有was,就共用一个was.
D Use of the pronoun it makes this construction a main clause, in which case the comma after communication must be omitted and began must be used to be parallel to merged; was...begun is not he correct tense.
变成了有主语的完整句子,但是was begun不是正确的时态表达
变成了有主语的完整句子,但是was begun不是正确的时态表达
it可以不用,begun不对,没有被动
Use of the pronoun it makes this construction a main cluase, in which case the comma after communication must be omitted and began must be used to be parallel to merged; was...begun is not he correct tense.
The function of ",": it was.......begun......and ...merged
it was more---wordy begun-began
begun和merged不平行 was begun用法错误 it was 没必要
begun形式不对
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