Vitamin C helps our bodies make a special chemical, which _______ affects our brains, making us feel happy.
| A．in all | B．in turn | C．in advance | D．in short |
There’s no way of knowing why one man makes an important discovery ___ another man, also intelligent, fails.
| A．since | B．if | C．as | D．while |
The doctor will see you again next week. _____, you must rest as much as possible.
| A．Somehow | B．However | C．Meanwhile | D．Indeed |
Of all the books on the shelf,is of any use for improving our practical skills of survival in the competitive world.
| A．nothing | B．no one | C．neither | D．none |
—How was your recent trip to England?
—I’ve never had ______ one before.
| A．the most pleasant | B．a more pleasant |
| C．a most pleasant | D．a pleasant |
When you talk about a person’s _____, you are referring to the country, race, or social class of their parents or ancestors.
| A．origin | B．nationality | C．generation | D．relation |