Which of the following statements concerning adverbial clause of time is NOT true()?
B.“As” can also be used when we want to say that when one thing changes, another thing changes at the same time
C.In formal speech and writing, we can often leave out “subject + be” in clauses with “when” and “while” if the main and subordinate clause refer to the same subject
D.“While” is used when you are mentioning a time or event in the past and indicating that a situation has continued from then until now