A:I think so.
B:I'm not surprised.
C:Of course.
D:Not likely!
An elephant has a _____nose.
继____ 狠____ 异____ 蹈____ 悔____
断____ 狼____ 导____ 踏____ 诲____
凸透镜焦距为13cm,若物体距它的距离为21cm,则所成的像是( )