设幂级数的收敛区间为(-2,6),的收敛区间为()
B
古埃及的 "金字塔时代 "是指 ()
When I came through the customs at the airport, I had to pay ________ on a clock I had bought.
设二阶可导函数,则()
How long ________ they ________ (dig) the ditch?
The student found the novel _______. It provided him with so much information about the subject.