Over 20% of the students at that school _____ the habit of smoking, which is beyond imagination.
| A．is | B．are | C．has | D．have |
Why not take up some outdoor sports to relax ______ office work? It will also help keep you healthy.
| A．for | B．from | C．on | D．of |
______ you are familiar with the author’s ideas, try reading all the sections as quickly as possible.
| A．Now that | B．Ever since | C．In case | D．As long as |
No one can walk the wire in the air without a bit of fear unless ______ very young.
| A．having trained | B．trained |
| C．to be trained | D．being trained |
After ______ seemed an endless wait, it was her turn to enter the general manager’s office.
| A．that | B．how | C．what | D．why |
The most delicious bread in the world ______ by Mom. Please wait an hour to enjoy it.
| A．bakes | B．is baked | C．is baking | D．is being baked |