一Julia,you look upset.What's up?—The computer_______break down at this busy hour.I have lots of typing to do.
It was not until dark _____ he found _____ he thought was the correct way to solve the problem.
_________ this is the biggest mistake we have made.
It i s the second time that the poor area_______.
In modern times, the development of science is ________ .
He insisted that his plan _______ carried out at once.