This is my school. There are many trees and flowers in it. The teaching building is big and tall. There is a big playground in our school. After 4:30 in the afternoon, many students come to the playground to play football and some students play table tennis in the table tennis room.
There are 1,200 students in 25 classes in our school. The students all like to study. The teachers in our school are very good. They help the students to study and the students like them, too.

荒漠中生活的骆驼刺，地下的根比地上部分长的多，这主要是（　　）

函数$y=ae·e^{\frac{b}{x}}$在$(0,+\infty )$上的图像如图所示（其中e为自然对数底），则$a,b$值可能是（  ）