His study was a mess with lots of books and magazines __________up everywhere.
| A．to pile | B．having piled |
| C．piled | D．to be piled |
I took my driving license with me on holiday，________I wanted to hire a car.
| A．in case | B．even if |
| C．ever since | D．if only |
It’s not easy to change habits，________with awareness and selfcontrol，it is possible.
| A．for | B．or |
| C．but | D．so |
Don’t turn off the computer before closing all programs，________you could have problems.
| A．or | B．and |
| C．but | D．so |
I was glad to meet Jenny again，________I didn’t want to spend all day with her.
| A．but | B．and |
| C．so | D．or |
There’s no way of knowing why one man makes an important discovery________another man，also intelligent，fails.
| A．since | B．if |
| C．as | D．while |