Without the earth’s atmosphere to protect them, astronauts can be exposed to intense radiation from the sun, ____ them at risk of cancer.
| A．to leave | B．leaving | C．having left | D．left |
______ Chief Engineer, as his family had expected, made his father happy and proud.
| A．Mike being appointed | B．Mike’s appointed |
| C．Mike appointing | D．Mike’s being appointed |
Storm chasing is so dangerous that some chasers are often hurt in accidents ______ by driving in a heavy rain.
| A．having caused | B．caused | C．to be caused | D．causing |
Believe it or not, crying is a way you can imagine ______ pressure.
| A．relieving | B．to relieve | C．relieved | D．relieve |
All the clothes donated by the citizens need cleaning thoroughly before being sent to the earth-stricken area, ______ ?
| A．needn’t they | B．don’t they | C．didn’t they | D．shouldn’t they |
My friend has returned from the UK. She ______ at Oxford for four years, during which we communicated with each other on the Internet.
| A．studied | B．has studied | C．had studied | D．has been studying |