It’s said that this kind of plant only gives off this strange perfume on ________ conditions which the scientists are trying to figure out now.
| A．outstanding | B．certain |
C．obvious | D．ordinary |
The policemen set out _________ the streets for the missing girl.
| A．searching for | B．to search | C．to search for | D．to search in |
_________ the website of the Fire Depart-ment in your city, and you will learn a lot about firefighting.
Having searched B. To search C. Searching D. Search
Why don't you bring _________ to his attention that you're too ill to work on?
| A．that | B．it | C．this | D．him |
Twenty students want to attend the class that aims to teach _________ to read fast.
| A．what | B．who | C．how | D．why |
Many of them turned a deaf ear to his ad-vice，_________ they knew it to be valuable.
| A．as if | B．now that | C．even though | D．so that |