The man said he saw a UFO.but when he took out of his camera ( )had disappeardA.that B.it 选哪个为什么?
问题描述：
The man said he saw a UFO.but when he took out of his camera ( )had disappeard
A.that B.it 选哪个为什么?
答
b.it用于原物的替代,that用于同种事物的替代.这里肯定是指UFO,所以是原物的替代