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
_______ the pull of the earth, a rocket must reach a speed of 28440 km/h.
A. In order to flee B. So as to escape
C. To escape D. So that to flee