_____to nuclear radiation, even for a short time , may produce variants(变异体) of genes in human bodies.
| A．Being exposed | B．Having expose |
| C．Exposed | D．After being exposed |
When you visit a museum you must ask for _____ before taking photographs inside it.
| A．promise | B．permission | C．consideration | D．support |
If the computer should_____ within the first three years, we would repair it at our expense.
| A．break up | B．break down | C．break off | D．break out |
Only with the greatest of luck _____to escape from the rising flood waters.
| A．managed she | B．she managed | C．did she manage | D．she did manage |
Why don’t you bring _____to his attention that you are too busy to do it?
| A．it | B．this | C．that | D．what |
The teacher rather than the students _____ referring to Reading Skills that _____newly published in America.
| A．is; was | B．is; were | C．are; was | D．are; were |