题干
When I stayed in the countryside, I enjoyed ____ leisurely walk in the fields, and felt ____ warmth of the sun on my face.
A：/ ; the
B：a ; a
C：/ ; a
D：a ; the
答案(点此获取答案解析）
C
}(n=
)满足
,且当
时,
. 若
, 
，则符合条件的数列{