Scientists say it will be five or six years ________ it is possible to test this medicine on humans．
| A．after | B．before | C．since | D．When |
. ________ we’ll go camping tomorrow has kept us all excited the whole day.
| A．If | B．Whether | C．That | D．Where |
. ________ we’ll go camping tomorrow depends on the weather.
| A．If | B．Whether | C．That | D．Where |
. ________ his failure lies is expected ________ clear to us.
| A．What… to make | B．How… made |
| C．Where… to be made | D．Why… Making |
. It is pretty well understood ________ controls the flow of carbon dioxide in and out the atmosphere today.
| A．that | B．that what | C．what | D．how |
主从复合句
名词性从句：主语、表语、宾语与同位语从句及其连接代词、连词与副词
. It didn’t surprise us at all ________ he was post to Hong Kong.
| A．why | B．how | C．what | D．that |