The CDs are on sale!Buy one and you will get___________completely for free．
A．it B．others C．that D．one
Whether the children have______fun in school has become________public concern．
A．/;a B．/；/ C．the；the D．the；a
— Can I pay the bill by check?
—Sorry, sir. But it is the management rule of our hotel that payment _______ be made in cash.
A. shall B. need C. will D. can
My teacher praised me for _____ progress I’d made, which was ____ great encouragement to me.
A. a; the B. /; a C. the; a D. /; /
Due to the widespread ________ of this medical technology，more diseases can be discovered and treated at an early stage.
A．presentation B．application C．qualification D．appreciation
The book was written ______ careful observations and detailed studies.
A. on behalf of B. regardless of C. on the basis of D. in relation of
