下列现象中不可用光沿直线传播解释的是　 [ ]

A． 小孔成像

B． 立竿见影

C． 日食

D． 湖面上的倒影

Don’t you know that Australia was, as a matter of fact, _________ used to be a nation of prisoners!

A．where

B．what

C．which

D．that