TFS阿尔卑斯系列的功效?
参考答案:
适合油性混合性肌肤,补水保湿清爽,收毛孔,抗辐射
----- Can you use chopsticks, John?
----- ________ . I once stayed in China for two years.
A.No problem
B.It all depends
C.I’m sorry, but yes
D.You can forget it
证明:当n为正整数,且nπ≤x(n+1)π,有2n≤S(x)<2(n+1).