In Paris nowadays, we may see musicians performing in the streets to ______.
| A．audiences | B．visitors | C．travelers | D．passers-by |
There were beautiful clothes________in the shop windows.
| A．spread | B．displayed |
| C．exposed | D．located |
_______you study hard，you’ll succeed in time.
| A．As far as | B．As long as |
| C．As good as | D．As well as |
He tried his best to solve the problem，________difficult it was.
| A．however | B．no matter |
| C．whatever | D．although |
Measures have been taken to prevent the river from____．
| A．having polluted | B．being polluting |
| C．being polluted | D．to pollute |
Children often display an________curiosity about every new thing they encounter.
| A．impossible | B．unreliable |
| C．extra | D．incredible |