Scientists say it may be a few years ______ it is possible to test the new medicine on patients．
| A．because | B．after |
| C．since | D．before |
yogurt do you need?
| A．How long | B．How many | C．How much | D．How old |
Mary is gooddrawing.
| A．for | B．at | C．to | D．with |
The teachers never arrive late for work from Monday to Friday.
| A．on weekends | B．on weekdays |
| C．every day | D．five times a week |
My uncle is leaving for Nanjing at 10:00 tomorrow.
| A．going to | B．going away | C．going from | D．staying to |
What’s your sister doing at the moment?
| A．soon | B．today | C．later | D．now |