The old man has two sons, ____________ are working in the supermarket.
| A．both of whom | B．each of them |
| C．both of them | D．all of whom |
The girl looked at me with a _____ expression. Maybe the problem was quite _____.
| A．puzzled; puzzling | B．puzzling; puzzled |
| C．puzzled; puzzled | D．puzzling; puzzling |
---Why do you look so happy?
---My aunt has bought a new car and she will invite me to go for a _____ this weekend.
| A．surf | B．ride | C．run | D．hike |
Free medical service is _____ to all the members of the factory.
| A．possible | B．available |
| C．enthusiastic | D．worthwhile |
Many things _____ impossible in the past are quite common today.
| A．having being considered | B．considered |
| C．are considered | D．considering |
Have you ever been to Mount Huangshan, _____ is famous for its towering pine forests and "sea of clouds"?
| A．which | B．where | C．that | D．what |