单句语法填空
1．By around 900 AD, there were many places in Northern Europe where the Vikings chose to live.
2．They hired two boats in_which they came up to the south of the river.
3．Eric reached Greenland and discovered that people could live in the place where he landed.
4．There are 30 students in my class having passed the exam, of_whom only 3 are boys.
5．In the year 1002, when Eric the Red's son Leif was planning a trip further west, Biarni was the man with_whom Leif discussed his plans.
