People are advised to be _____ towards the health concerns of their dear ones while burning firecrackers to celebrate the festival, for they contain harmful chemicals．
| A．accessible | B．aware | C．cautious | D．sensitive |
Should the opportunity _________，I'd love to go to Paris.
| A．rise | B．raise |
| C．arise | D．happen |
_________ found my wallet, Tom?
| A．Where did you that | B．Where was it you |
| C．Where have you that | D．Where was it that you |
It was not until 1920_________ regular radio broadcast began.
| A．while | B．which |
| C．that | D．Since |
It was in the factory _________ produced TV sets _________ I got to know her.
| A．which; which | B．that; which |
| C．that ；that | D．where ； that |
Factory workers have to work very hard, and _________.
| A．farmers do so | B．farmers work so |
| C．so have farmers | D．so do farmers |