Students should be ________ in class.Only listening without taking part in the activities is not good for one’s study.[ ]

Must I turn off the gas after cooking ? –Of course You can never be ___ careful with that

Nino Hernandez,who ________ only 10kg and is regarded as the world’s shortest living man,has not grown since he was 2 years old[ ]

I won’tpass the exam ______I work hard..

The lawyer seldom wears anything other than a suit __________the season.