某有机物的化学式为C₅H₁₀O，它能发生银镜反应和加成反应．若将它与H₂加成，所得产物结构式可能是（   ）

— I want to learn tennis. Would you like to help me?
—        . But learning tennis is no walk in the park.    

函数$f\left(x\right)=a{x}^3+b{x}^2+cx+d$图象如图,则函数$y=a{x}^2+\frac{2}{3}bx+\frac{c}{3}$的单调递增区间为(      )

The novel “The Da Vinci Code”        a great success and was translated into 44 languages in 2004.

（2008·山东基本能力，9）“一万年太久，只争朝夕”，警示人们要珍惜年华。古人对时间的体验与此类似的是                                                                                       （   ）
①子在川上曰：逝者如斯夫，不舍昼夜 ②人世几回伤往事，山形依旧枕寒流 ③落霞与孤鹜齐飞，秋水共长天一色 ④叹长河之流速，送驰波于东海