题干
The dining hall is ________ to hold 300 people.
A：enough big
B：enough small
C：small enough
D：big enough
答案(点此获取答案解析）
D
The dining hall is ________ to hold 300 people.
A：enough big
B：enough small
C：small enough
D：big enough
满足
成等比数列，
项和，则 
的值为