Scientists generally agree that Earth's climate will warm up over the next 50 to 100 years __________ it has warmed in the 20,000 years since Ice Age.
| A．as long as | B．as much as |
| C．as soon as | D．as well as |
True friendship is like sound health, whose value is seldom known it is lost.
| A．when | B．though | C．until | D．unless |
People ______ long distances frequently have to decide whether they would prefer to go by land, sea or air.
| A．to travel | B．travelled | C．travel | D．travelling |
______ your plans look good, you still need to do some revision work on it.
| A．If | B．Once | C．Although | D．Since |
The prices of houses ______ because the demand of them become more and more great.
| A．are rising | B．rise | C．had risen | D．have been risen |
Compared with the nervousness of driving in the rain or snow, it is ______ to sit in a train without any worry of bad weather.
| A．more tired | B．less tiring | C．less tired | D．even more tiring |