将下列陈述句改成疑问句

①小姑娘天真的心灵，正像一个含苞欲放的花蕾。 ②这些树叶就是从这棵树上飘落下来的。

为加强防汛工作，某市对一拦水坝进行加固，如图，加固前拦水坝的横断面是梯形ABCD．已知迎水坡面AB=12米，背水坡面CD=12 $\sqrt{3}$ 米，∠B=60°，加固后拦水坝的横断面为梯形ABED，tanE= $\frac{3}{13}\sqrt{3}$ ，则CE的长为____米．

阅读理解

These amazing animals prove that love lives on four legs.

A little girl's lifeline

Three-year-old Alida Knobloch and her 27kg golden dog, Mr. Gibbs, are almost together all the time. There is a special love between them. Alida, who suffered from serious lung (肺)disease when she was 10 months old, is unable to breathe on her own for about 45 minutes. So Mr. Gibbs has been with her everywhere, carrying 4.5kg of oxygen tanks for her. A pig that calms kids

   When Lois Brady, a famous doctor in America, visits special-needs students in San Francisco schools, she often brings along Buttercup, a black pig from Vietnam. The pig is very calm and friendly and has been trained to offer comfort to patients as well.

A Lion's big heart

   With paws the size of dinner plates, bright black eyes and a golden mane (鬃), Jupiter, a 13-year-old 250kg lion, was brought to the rescue (援救) center by Anna. In the past two years, Anna has developed a very close relationship with Jupiter.

影响西北地区畜牧业发展的主要问题是（　　）