Listening to loud music at rock concerts ________ caused hearing loss in some teenagers．

A．is

B．are

C．has

D．have

Tim is in good shape physically ________ he doesn't get much exercise．

A．if

B．even though

C．unless

D．as long as

We'll be free tomorrow, so I suggest ________ to the history museum．

A．to visit

B．visiting

C．we visit

D．a visit

He is only too ready to help others, seldom, ________ , refusing them when they turn to him．

A．if never

B．if ever

C．if not

D．if any

I've become good friends with several of the students in my school ________ I met in the English speech contest last year．

A．who

B．where

C．when

D．which

I was just going to cut my rose bushes but someone ________ it．Was it you?

A．has done

B．had done

C．would do

D．will do

Dina, ________ for months to find a job as a waitress, finally took a position at a local advertising agency．

A．struggling

B．struggled

C．having struggled

D．to struggle

The poor child stood there, and ________ what to do, turned to his father for help．

A．not knowing

B．not knew

C．not to know

D．not know

This coastal area ________ a national wildlife reserve last year．

A．was named

B．named

C．is named

D．names

Mark Zuckerberg is the founder of the site Facebook, ________ you can have a look at each other's pictures．

A．where

B．which

C．when

D．as