___is known to us all is that the old worker, for _______ life was hard in thepast, still works hard in his seventies

We are bound to solve the present severe problem, ________ we act intelligently and promptly.

The notebooks aren’t here. Please _the teacher _ them.

Why does Wei Fang study so hard—She studies hard _________ she can get into a good university.

bout the result —Well, it remains _______whether we’ve gotenough support.