26. It is difficult to do some of the experiments ________ in our physics textbooks.
The door________open,no matter how hard she pushed.
No one________ be more generous;he has a heart of gold.
—Why are your eyes so red?You________have slept well last night.—Yeah,I stayed up late writing a report.
Harry is feeling uncomfortable.He________too much at the party last night.
—You needn't take an umbrella.It isn't going to rain.—Well, I don't know.It________do.