It was not until the teacher had explained it three times _______ how to work out the problem.
| A．did he understand | B．had he understood |
| C．that he understood | D．that he didn’t understood |
_____ all the inventions have in common is ______ they have succeeded.
| A． What; what | B． That; what |
| C． What; that | D． That; that |
No matter where he is, he makes ________ a rule to go for a walk before breakfast.
| A．him | B．this |
| C．that | D．it |
If he had insisted that heto work there then, everything would be OK now.
| A．sent | B．be sent |
| C．had been sent | D．was sent |
Professor Smith, along with his assistants, on the project day and night to meet the deadline.
| A．work | B．working |
| C．is working | D．are working |
—It is said that you have won the first prize in the English contest.
—. English is not my cup of tea.
| A．Don’t pull my leg | B．Don’t be a wet blanket |
| C．I’m all ears | D．It’s a piece of cake |