Babies sleep l6 to l8 hours in every 24 hours, and they sleep less ________ they grow older.
| A．while | B．as | C．when | D．after |
He brought me a few magazines but，to my disappointment，___was to my taste.
| A．nothing | B．no one | C．neither | D．none |
The world today _____ different without the amazing discoveries produced by great scientists.
| A．were | B．had been |
| C．would be | D．would have been |
No one knows for certain how the first Americans arrived in _____ is now the United States.
| A．which | B．what | C．where | D．why |
A journal is not necessarily a reliable record of facts, for the writer’s impressions _____ colour the telling of events.
| A．must | B．shall | C．should | D． might |
She seated herself at a small table in the restaurant, waiting _____.
| A．serving | B．to serve |
| C．served | D．to be served |