The possibility____ pleasant smells might reduce pain has recently been suggested by new research.
| A．which | B．why | C．that | D．whether |
On workday mornings I usually ________ an hour driving to work because of the traffic jam.
| A．spent | B．am spending | C．spend | D．will spend |
the website of China Daily, and you will learn more about it.
| A．Having searched | B．Search |
| C．Searching | D．To search |
____ has helped to protect the environment is worth praising.
| A．Who | B．The one | C．Anyone | D．Whoever |
—Why didn’t Tom go to the concert last night ? — I have no idea, but I think he _____ in his study.
| A．read | B．have read |
| C．was reading | D．would read |
Being examined twice a year is the rule that every driver _____ obey in this city.
| A．shall | B．can | C．ought to | D．need |