_______you come or not is up to you.
| A．What | B．If | C．Why | D．Whether |
_____ the ladder, get someone to hold it.
| A．When climbed | B．When to climb |
| C．When climbing | D．When one climbs |
Don't leave your work half _____.
| A．being done | B．doing | C．to do | D．done |
Any student,who is thougnt ______ the rules, for example, by cheating, has _____ before a student court.
| A．to have broken; to appear | B．to break; to get |
| C．broken; taken | D．to break; to be taken |
Prices of daily goods _____ through a computer can be lower than store prices.
| A．buying | B．bought | C．are bought | D．been bought |
______ in the chimey for five hours, the thief looked very pale and tired.
| A．Having been trapped | B．Being trapped |
| C．trapping | D．Having trapped |