It is uncertain ___ side effects these weight-loss drugs will bring about, although hundreds of thousands of patients have taken it.
| A．that | B．whether | C．how | D．what |
______life began on the earth is one of the biggest puzzles to scientists.
| A．How | B．What | C．Where | D．That |
---Let’s throw a surprise party for mom’s 50th birthday.
---That’s a good idea. We________several of her friends.
| A．invite | B．have invited | C．are inviting | D．will invite |
________fit, we ought to learn more about our body and be careful with what we eat.
| A．Keeping | B．To keep | C．Having kept. | D．To have kept |
Mike must be angry with me, for he walked________me without even saying hello.
| A．past | B．on | C．at | D．over |
In middle schools all over China, boys_____not to wear their hair long.
| A．will be requested | B．have requested | C．are requesting | D．are requested |