单项选择题
A．whom B．that C．which D．what
No plant can possibly exist on the moon because there i...
单项选择题No plant can possibly exist on the moon because there is no water,（）is indispensable to life.
A．that B．which C．it D．of which
I hope that the little（）I've been able to do has been o...
单项选择题I hope that the little（）I've been able to do has been of some use.
A．which B．what C．whose D．that
He is regarded by all as a genius,（）the important disco...
单项选择题He is regarded by all as a genius,（）the important discovery was made.
A．who B．whom C．about whom D．by whom
