—Who called just now, Sam?—It’s Mona. She asked _____.
I am not sure if Tom____ home. If he________, I'll call you.
It_______ me 15 minutes to get to school on my bike.
------Why are you so________?-------I am watching an_______ basketball match.
The math problem is too difficult ,I can’t__________ .
Many old men prefer __________ in a peaceful countryside.