According to an annual UC survey of first-year students, freshmen now list ____ as the most important reason to go to college.

深度为k具有n个结点的完全二叉树，其编号最小的叶结点序号为⌊2k-2⌋+1。 A、正确 B、错误

判断题深度为k具有n个结点的完全二叉树，其编号最小的叶结点序号为⌊2k-2⌋+1。
A、正确
B、错误

草地混播中混播组合适宜比例维持较容易，但筛选难度较大。 A、正确 B、错误

单项选择题草地混播中混播组合适宜比例维持较容易，但筛选难度较大。
A、正确
B、错误

It was  not until Father came back   ___  we bagan to h...

单项选择题It was  not until Father came back   ___  we bagan to have supper last  night.
A、the time
B、 when
C、that
D、 which