This is the tallest tree ( )I've ever seen.A that B which C 不填 D that 或不填 选A 还是D

问题描述:

This is the tallest tree ( )I've ever seen.A that B which C 不填 D that 或不填 选A 还是D

This is the tallest tree ( )I've ever seen.
选D
这是一句定语从句,先行词被*修饰,只能用that
因为作宾语,所以还可以不填