A cook will be immediately fired if he is found _______ in the kitchen.
| A．smoke | B．smoking | C．to smoke | D．smoked |
Vitamin D helps our bodies make a special chemical，and this special chemical，________，affects our brains，making us feel happy.
| A．in turn | B．in particular |
| C．in advance | D．in short |
Some of us remain________at our computer for hours every day，forgetting moving our body.
| A．seating | B．seated |
| C．sat | D．sit |
—As a teenager，our son should have two or three hobbies to be really happy.
—________，but how can he afford the time with so much homework every day?
| A．So does he | B．So he does |
| C．So should he | D．So he should |
We pursue happiness，thinking one day we will find it.But_________it by seeking it.
| A．rarely will we find | B．rarely we will find |
| C．rarely will find we | D．rarely find we will |
Some fruits are so easily harvested in this area that they are never of great________.
| A．fare | B．benefit |
| C．help | D．worth |