—Must he finish the work before lunch?
— ___________. He can do it in the afternoon.
A:Yes, he must.
B:No, he mustn't.
C:No, he needn't.
小郭投篮动作优美,其在运动中起支点和动力作用的分别是( )
下列动物中,不属于腔肠动物的是( )