--- Isn't that Ann's husband over there?--- No, it ______ be him---I'm sure he doesn't wear glasses.
We are pleased with the fact that the people in the poor area are proud of what they ______ in the past 10 years.
Only ______ a human being.
My English teacher gave us a suggestion yesterday, _____is often the case, ______our monitor organize a debate after class.
It was three months later _____ he completed the job with difficulty.
It ___________last night, for the ground is wet outside.