—Have you ____ been to our town before?—No, it’s the first time I ___ here.
The couple ________ a health centre in Cambodia,________ their seven year old son was born.
There used to be a mountain in our village, at the top of which ________.
It was along the Mississippi River ________ Mark Twain spent much of his childhood.
Linda,make sure the tables ________ before the guests arrive.
________caused the accident is still a complete mystery.