—I wonder _________ Mary has kept her figure after all these years.

—By working out every day.

A. where                 B. how

C. why                  D. If

The exhibition tells uswe should do something to stop air pollution.

A. where      B. why

C. what         D. which

If you swim in a river or lake, be sure to investigate  is below the water surface. Often there are rocks or branched hidden in the water.

A. what               B. who

C. that                D. whoever

I truly believe ______beauty comes from within.

A. that                B. where

C. what                 D. why

You have to know ________ you're going if you are to plan the best way of getting there.

A. what                  B. that

C. where                  D. who

I took my driving license with me on holiday,  ________ I wanted to hire a car.

A. in case             B. even if

C. ever since           D. if only

In the global economy, a new drug for cancer, ________  it is discovered, will create many economic possibilities around the world.

A．whatever          B．whoever

C．wherever          D．whichever

She says that she'll have to close the shop ________ business improves.

A. if                 B. unless

C. after              D. when

Mark needs to learn Chinese ________his company is opening a branch in Beijing.

A. unless                B. until

C．although             D. since

________ I have to give a speech, I get extremely nervous before I start.

A. Whatever              B. Whenever

C. Whoever              D. However