— It’s getting dark, but Mr. Chen is till at his office.
— No surprise. Who else can _______ he does.
| A．do less work than | B．work as hardly as |
| C．work as hard as | D．be working hardly like |
_________ life will continue on the earth for millions of years to come will depend on __________ this problem can be solved.
| A．If; that | B．Whether; if |
| C．If; whether | D．Whether; whether |
--May I open the window to let in some fresh air?
-- __________
| A．Come on. | B．Take care. |
| C．Go ahead! | D．Hold on! |
__________ is even more important is _________ the earth cooled down, water began to appear on its surface.
| A．What; that as | B．It; which |
| C．It; which as | D．What; which |
If you ______ smoke, please go outside.
| A．can | B．should | C．must | D．may |
His eyes stare _________ is left of the brother’s dinner on table.
| A．in which | B．at what |
| C．in what | D．at which |