Itis__________thattextmessagingwhiledrivingisdangerous.
A: necessary
B: sufficient
C: obvious
D: significant
A: necessary
B: sufficient
C: obvious
D: significant
举一反三
- Itis _________forustogoswimminginsuchbadweather. A: important B: impossible C: necessary D: comfortable
- Itis necessary to a large vocabulary in learning a language.
- If you want to learn a language well, ________ time is necessary A: sufficient B: favourable C: somewhat D: ewarding
- It is absolutely necessary for us to have sufficient oxygen if we （）to go on living A: are B: were C: had D: having
- What is the single necessary and sufficient condition for a business? 对于一项业务来说，哪一项是充要条件？