猪笼草是一种食虫植物，为了验证猪笼草分泌液中有蛋白酶，某学生设计了两组实验，如下图所示。在35 ℃水浴中保温一段时间后，甲、乙试管中加入适量的双缩脲试剂，丙、丁试管中不加任何试剂，下列实验能达到目的的是(　　)

同学们，你知道世界读书日吗？每年的4月23日是世界读书日，由联合国教科文组织在1995年设立，目的就是鼓励人们多读书。然而，许多人不爱读书。据调查，人们每天花在阅读上的时间只有15分钟。请你谈一谈为什么要读书，应该读什么样的书，并向你的同学发出倡议。

注意：1）词数100个左右；

     2）短文的开头已写好，不计入总词数；

     3）短文必须包括所有内容要点，行文连贯，表达清楚，书写规范。

参考词汇：联合国教科文组织the UNESCO 调查survey

Dear friends, do you know about World Reading Day?

“东方之星”沉船事故救援时，潜水员钢瓶中携带的气体是(   )

一束光与镜面成30°角照射到平面镜上，则反射角为   ____ °

    When the plane was waiting at the airport, a big snake climbed up the steps and into the plane. It went to sleep under the pilot's (飞行员的) seat. Nobody saw it. Soon the passengers (乘客) walked into the plane and it took off. A little girl called Mary took out a whistle (哨子) and began playing. But none of the passengers liked the music. Then the stewardess (女乘务员) asked Mary to stop.

    The noise of the plane woke the snake. It put its head out and looked into the pilot's room. The pilot saw the snake and was greatly afraid. He was very afraid that the snake would bite him so he could not control the plane, and the plane started to swing strongly from side to side. The stewardess told the passengers what was happening and asked them not to be afraid. Mary was not afraid at all. She ran to the pilot's room with her whistle and began to play slow music, then the snake went after her. The girl returned to her seat and the snake lying on the floor beside her, dancing to the music.

    When the plane finally landed at the airport, and people took the snake to a zoo near Mary's house. She often went to visit the snake.