—How many subjects are you good at? —Three, ____, English, Chinese and politics.
----How unhappy your roommate looks! ----Yes,but he’s not willing to tell me what it is____ is troubling him.
It was along the Mississippi River _______ Mark Twain spent much of his childhood.
It was not until midnight __ they reached the camp site.
It was in New Zealand ___ Elizabeth first met Mr. Smith.
----Where did you get to know her? ------It was on the farm ____we worked.