We can have ________ bluer sky if we create _________less polluted world.
| A．a; a | B．a; the |
| C．the; a | D．the; the |
_______ the little girl was hit by a truck, nobody gave a hand to the girl ______ an old lady appeared. Why were they so cold-hearted?
| A．When；while | B．Before; until |
| C．After；until | D．As； while |
—She didn’t make ______ great progress，did she?
_______，although she did her best.
| A．so； No | B．so； Yes |
| C．such; No | D．such；Yes |
I think it's well worth ______ our best to learn a second language well.
| A．to try | B．trying | C．try | D．tries |
The thing that matters is not whether you fail or not, _______whether you try or not.
| A．and | B．or | C．so | D．but |
_______ Mrs. Zhang ______ Dr. Yang shows great interest in the topic we are talking about. They want to know more about it.
| A．Both； and | B．Either； or |
| C．Not only；but also | D．Neither； nor |