当前防治流感最有效的方法是

A．每天服维生素C

B．吃好睡好

C．流感病毒疫苗免疫接种

D．服用抗流感病毒药物

E．体育锻炼

My brother usually _____ his classroom after school. But now he _____ basketball.

A．cleans; plays

B．is cleaning; plays

C．cleans; is playing

D．is cleaning; is playing