Doctor Wang at seven o’clock for the conference, but she didn’t turn up.
| A．should have arrived | B．should arrive |
| C．should be arrived | D．should be arriving |
The bus hit against a tree in the fog and __________to the deep valley, with ten passengers killed and twenty wounded.
| A．down did it roll | B．down rolled it | C．down it rolled | D．it down rolled |
Understanding the cultural habits of another nation, especially ____________ containing as many different subcultures as the United States, is very difficult.
| A．one | B．that | C．some | D．the one |
As we all know, apples are sold by ____ weight, and socks are sold by _______dozen.
| A．the; a | B．/; a | C．/; the | D．the; the |
Many difficulties have ______ as a result of the changeover to a new type of fuel.
| A．risen | B．arisen | C．raised | D．arose |
——Why are the tax collectors so busy?
——Many people prefer to have their tax forms completed by a professional rather than ___.
| A．do it themselves | B．doing it themselves |
| C．to do it themselves | D．done by themselves |