—I have a headache.
—I’m not surprised you ________ in front of the computer for too long.
| A．work | B．are working | C．have been working | D．had worked |
I'll make some sandwiches, just ________ we get hungry later.
| A．even if | B．as though |
| C．if only | D．in case |
You know that some people say more but do less ________ others do the opposite.
| A．once | B．while | C．when | D．as |
The professor told me to start the research right now, ________ I was sure to fall behind.
| A．or | B．so | C．but | D．and |
________ a man's age, he can reduce it several years by wearing a confident smile.
| A．Whichever | B．Whatever |
| C．Whenever | D．However |
After a year, doctors diagnosed him with a disease so rare ________ it affects just one in 8 million children.
| A．after | B．that | C．as | D．since |