单项选择题
They（）each other for more than twenty years.
A.don't see B.didn't see C.haven't seen D.hadn't seen
单项选择题 These desks and chairs（）to the children in the mountain villages next week.
单项选择题 Therefore, other things（）equal, the number of workers that employers want decreases.
单项选择题 There is（）water in the glass, is there?
