Not until it was completely dark______working.A．had they stoppedB．they stoppedC．they didn"

It was___that they began to handle the major problem.A.until late afternoonB.not until lat

It is not until the early 1970s that the Vietnam War was brought to a close by PresidentA．

It was not until 1920 ______ regular broadcast began.A、whileB、whichC、thatD、since

It was not until dark he found he thought was the correct way to solve the problem.A．that；whatB．that

It was not until she had arrived home her a

It was____back home after the experiment.[ ]A. not until midnight did he goB. until midnight that he