A man has a cat. He likes her very much. At mealtime the cat sits at the table with him. The man eats with a knife and a fork, but the cat eats from her plate. Sometimes, when she finishes her dish, her master will give her a bit of his food. He shares his meal with her. One day the cat is not at the table at mealtime.

    “Ah! Where is my cat?” asks the man.

His wife says, “Can't you eat without her?”

       So the meal begins without the cat. Before lunch is over, the cat rushes into the room and jumps onto the chair quickly. She has two mice in her mouth, and before anyone can stop her, she drops(扔下) one into her own plate, and the other into her master’s plate.

    “Dear me!” cries the woman, “A mouse is in your plate!”

    “Hush(安 静)!” says her husband. “This shows that she is a nice cat. She knows what friendship is. She wishes me to share her dinner as I often share mine with her, I am not so unhappy.”

下图是实验室用大理石与稀盐酸反应制取二氧化碳并验证其性质的实验装置图，试根据要求回答下列问题：

（1）标号a的仪器名称为____ ，实验室中还可用装置A制取的气体是____ ．

（2）装置B中反应的化学方程式为____ ，装置C中观察到的现象是____．

（3）装置D中观察到下层蜡烛先熄灭，上层蜡烛后熄灭，说明____ ．

（4）实验室用装置E来收集二氧化碳时，二氧化碳应从____ （填“c”或“d”）端通入．

（5）装置F可用来测量生成的CO₂气体的体积，其中在水面上放一层植物油的目的是____．