Three people got killed by two explosions.—When was __________?—________ was on April 15 __________ the 2013 Boston Marathon was being held．

If you don’t know a word, you may ______ in a dictionary.

I’m sorry I haven’t got any money. I’ve ______ my handbag at home.

Mr Smith is old man and he usually walks his dog after supper.

____ the English examination I would have gone to the concert last Sunday