Could you please do some shopping for me, Mary?— Sorry, I ______ my homework.
_________is very interesting to swim in the river in summer, but it’s dangerous.
He, together with his parents _______ going to visit Shanghai in July. How about you? —I’m afraid I have to stay at home _______.
Is the physics problem _________?—- Yes, I can work it out _________.
People are really ______________ on the beach in summer (夏季).