_ is known to us all that the old scientist, for _______ life was hard in the past, still works hard in his eighties.

___________ to enter an ideal university, he worked harder than ever before.

You say the manager might not agree to the plan ________, I will not put it forward in the meeting tomorrow morning.

He did not regret saying what he did but felt that he _____ it differently.

Who watered the flowers beside thewindow——Helen ____________.