I, who _____ your good friend, will share your joys and sorrow.
Although Jane agrees with me on most points, there was one on which she was unwilling to _______.
It was ______ the old clock that the old man spent the whole morning at home.
So convenient _______ to pay by credit card that more and more people apply for their credit cards.
I didn’t have to work all weekend — I did it by _______.
In fact, _______ one cause that leads to the problem.