无土栽培是现代农业的一项新技术，其营养液是多种化合物的混合溶液，含有植物生长所需的营养元素．某种植物进行无土栽培时，需含氮、钾等元素的中性或弱酸性营养液，下列能用来配制营养液的一组化合物是（  ）

如图，△ABC与△DEF位似，位似中心为点O，且△ABC的面积等于△DEF面积的$\frac{1}{4}$，则$\frac{AB}{DE}$= ____

根据短文内容，判断正确还是错误。

       My name is Li Hong. I'm 16 years old. I have a lovely brother. His name is Li Qiang. He was short and thin two years ago. He was 1.58 m. He was 48 kg. He was a primary school student. He often watched TV and played games. He didn't like playing football. Now he is handsome. He is 14 years old. He is a junior high school student. He is 1.65m. He is 56kg. He is tall and fat. He is very strong, too. Sometimes he watches TV in the evening. He doesn't play games. He plays football and rides a bike every day.

读“欧洲人的饮食结构深受自然环境的影响”图，判断M代表（　　）