Most experts agree that washing hands regularly is a ______way to prevent the spread of many diseases.
| A．powerful | B．illegal | C．painful | D．awful |
There were signs here and there, _____ visitors to look out for ______ rocks.
| A．warning; fallen | B．warned; falling | C．to warn; fallen | D．warning; falling |
I don't doubt ______ he will pass the tomorrow’s exam.
| A．that | B．whether | C．if | D．which |
We were ______ on our way to the airport because of the heavy snow.
| A．held up | B．held out | C．held on | D．held with |
______ all the required papers, he didn’t answer the questions fluently in class.
| A．Having not read | B．Not having read | C．Not read | D．Not to read |
When he reached the final line,everyone_____laughing.
| A．burst into | B．burst out | C．burst up | D．broke out |