It’s really difficult to ______ what he is trying to express.
| A．leave out | B．pick out |
| C．work out | D．make out |
Helen has just heard the news from her father ________ her boyfriend David will come back soon.
| A．when | B．how |
| C．which | D．that |
________ you said at the meeting describes a bright future for the company.
| A．When | B．How |
| C．What | D．That |
Time is of no importance to great thoughts, ________ are as fresh today as when they first passed through their authors' minds, ages ago.
| A．what | B．that |
| C．which | D．where |
Willpower is a kind of quality, ________ is ________ it takes to do anything well.
| A．what; which | B．what; what |
| C．which; which | D．which; what |
________ nearly all behavior is learned behavior is a basic assumption ________ has been put forward by social scientists.
| A．What; that | B．That; what |
| C．What; what | D．That; that |