A：人大肠杆菌容易寻找
B：大肠杆菌生产安全
C：大肠杆菌繁殖速度快
D：大肠杆菌易受人控制
In my opinion, all Mr White________ good to his students in his class at present. He is very strict in their study.
题墨葡萄诗
【明】徐渭
半生落魄已成翁，独立书斋啸晚风。
笔底明珠无处卖，闲抛闲掷野藤中。
【注】徐渭，字文长，明代文学家、书画家，屡应乡试不中，空有满腹经纶不得施展。水墨《葡萄图》，是徐渭的代表画作之一。
A man says to his friend，"Guess how many coins(硬币) I have in my pocket(兜). "
The friend says. "If(如果) I guess right，will you give me one of them？"
The man says，"If you guess right，I'll give you both(两个都) of them. "
（Ⅰ）将V表示成r的函数V（r），并求该函数的定义域；
（Ⅱ）讨论函数V（r）的单调性，并确定r和h为何值时该蓄水池的体积最大．
