______ he referred to in his article was unknown to the general reader.
| A．That | B．What | C．Whether | D．Where |
—I'd like a pen which ________ well.
—Will this one ________？
| A．writes；do | B．writes；work |
| C．is written；do | D．is written；work |
I like getting up very early in summer.The morning air is so good ________.
| A．to be breathed | B．to breathe |
| C．breathing | D．being breathed |
Professor Williams keeps telling his students that the future ________to the well－educated.
| A．belongs | B．is belonged |
| C．is belonging | D．will be belonged |
The water ________ cool when I jumped into the pool for morning exercise.
| A．was felt | B．is felt | C．felt | D．feels |
—What's that noise?
—Oh，I forgot to tell you.The new machine ________.
| A．was tested | B．will be tested |
| C．is being tested | D．has been tested |