一个圆锥的高为4cm，底面圆的半径为3cm，则这个圆锥的侧面积为（　　）

Woman：Can I help you ?

Anna：Yes, please .I need a new pants for school.

Woman：Ok. What colour do you want?

Anna：Blue.

Woman：How about this one?

Anna：It looks nice. How much are they?

Woman：They are fifty-four yuan.

Anna：I'll take it. How much are those yellow shoes?

Woman：Thirty-five yuan.

Anna：Great! I'll take them.

Woman：Here you are.

Anna：Thank you!

Woman: You're welcome.

某同学进行了“测定电源电动势和内电阻”的实验，将实验数据描绘得到如图（A）所示的图象．根据图象可得，该电源的电动势为____V，内电阻为____Ω；若该同学在实验时采用如图（B）所示的电路，则电动势的测量值与真实值之间的关系为E_测____E_真，内电阻的测量值与真实值之间的关系为r_测____r_真．

如图，AD，BC是⊙O的两条互相垂直的直径，点P从点O出发，沿O→C→D→O的路线匀速运动．设∠APB=y（单位：度），那么y与点P运动的时间x（单位：秒）的关系图是（   ）

写出下面有机物的结构简式：甘氨酸：　 ____，丙氨酸： ____.