As is widely accepted, _______ students should have ______ easy access to labs, libraries and other facilities at school.
| A./; an | B.the; an | C.the; / | D./; / | 
 Speaking of all the songs he has written, I think this is probably his _______ one.
| A.better-known | B.well-known | 
| C.best-known | D.most-known | 
 I would appreciate it _______ you call back this afternoon for the doctor’s appointment.
| A.that | B.if | C.which | D.whether | 
 We can never expect _______ bluer sky unless we create _______ less polluted world.
| A.a; a | B.a; the | C.the; a | D.the; the | 
 We all know that, _______, the situation will get worse.
| A.not if dealt carefully with | B.if not carefully dealt with | 
| C.if dealt not carefully with | D.not if carefully dealt with | 
 The fearless pirates kept _______ on the waters off the coat of Somalia, from the Gulf of Aden to the Kenya border along the Indian Ocean.

| A.knocking on | B.knocking down | 
| C.knocking about | D.knocking at |