. Many in the credit industry expect that credit cards will eventually _________ paper money for almost every purchase.
—You needn't take an umbrella.It isn't going to rain. —Well, I don't know.It ________ do.
When I was a child, I ________ watch TV whenever I wanted to.
I should not have laughed if I ________ you were serious.
The door ________ open, no matter how hard she pushed.
(2013·天津,9)No one ________ be more generous; he has a heart of gold.