31 It is in the year of 2010 a severe drought hits Yunnan province

More than 20 people ________ in traffic accidents ________ last May.

The astronauts have to lie ________ the floor of thespaceship to fight against the great pressure during the flight

He is poor _____ he is happy all the time.

Could you please come to the museum with me this afternoon—Sorry， I ______ . I have to take a piano lesson at 2 pm.