It is uncertain ________ side effect the medicine will bring about, although about two thousand patients have taken it.
The Medical Research Council said it could not _____ use of the new drug without further tests.
In an interview, don’t say anything negative about your employer---it gives a bad______.
Under the new policy, anyone who is found ______ in the school building will be fined $60.
The Internet is widely used, which ______ the development of English.
Only when she reached her office____ she had left her key at home.