小明同学在学习了羧酸的性质后，在家中进行了以下实验活动，其中_爱下问搜题

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问题选择题

小明同学在学习了羧酸的性质后，在家中进行了以下实验活动，其中不能达到目的是[ ]

A．利用食醋除水壶中的水垢

B．流感季节在室内熏蒸白醋以预防感冒

C．把白酒和食醋混合后加热制取乙酸乙酯

D．做某些菜时加入食醋以增强口感

答案

答案：C

选择题

化学实验既要操作规范, 更要保障安全。下列实验基本操作符合这一要求的是( )

阅读理解

We always regard dogs as man’s best friends. But what about cats?
Cats can also do us a favor sometimes.
Here is a comparison of the two animals.
A Friend Helps You When You’re Sick

Dogs	When Catherine lay down on the sofa, Pepe stared(盯) into her eyes and kept sniffing(嗅). After being pushed away, he suddenly jumped onto her chest. That’s when Catherine felt a pain that made her visit a doctor, and a fast-growing cancer was found. Months later, however, Pepe started staring and sniffing again. It seemed strange, but sure enough, Catherine’s cancer had spread.
Cats	Alana immediately finds a chair when Tee sits and stares directly into her face. That’s because Tee is warning her that she is about to faint(昏倒), which can happen as often as three times a day. But Alana won’t get hurt if she sits down. Not only does Tee warn Alana, but also her husband. Then the cat stays with Alana until she recovers.

A Friend Saves Your Life

Dogs	Ryan fell into the water by accident. The river was full of ice, and Ryan was very cold and his body temperature was dropping dangerously low. Luckily, he was found by Chelsea, who was playing with her dog, Zion. “Zion knew the boy was in trouble,” says Chelsea. “Ryan grabbed onto the dog’s collar, and Zion just turned around and came back to the bank.”
Cats	Bernice says: “I was sleeping in my bedroom, and then I was woken by Joey screaming and running”. Then she found smoke around her. With Joey helping her, she managed to get out of the door. “I found him in a mailbox when he was young and now I feel very lucky. Without him, I’d have probably died in the smoke.”

小题1:When Alana is about to faint, Tee will ________.

A．stare at her and keep sniffing	B．jump onto her chest suddenly
C．sit and stare directly into her face	D．scream and run

小题2:What can we learn about Ryan?

A．He likes swimming in rivers.

B．He has a lovely dog, Zion.

C．Chelsea helped him swim back to the bank.

D．He was in danger when he was found by Chelsea.

小题3:What happened when Bernice was sleeping?

A．She was badly hurt in a big fire.

B．She found the brave cat in a mailbox.

C．A fire broke out when she was sleeping.

D．She ran out of the burning house with the help of firemen.