用甲基橙指示剂滴定法测定水中侵蚀性二氧化碳时,打开采样瓶塞后应立即测定,滴定时应避免

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问题:

用甲基橙指示剂滴定法测定水中侵蚀性二氧化碳时,打开采样瓶塞后应立即测定,滴定时应避免强烈的摇动,以防止()。

考点:环境监测上岗考试环境监测上岗考试题库
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Do you like dogs? Do you know the following things about dogs?

The first pet dog

Dogs are meat-eating animals. They belonged to the family of wolves (狼) a long time ago. About 15,000 years ago, people started keeping wolves for hunting (狩猎). Over the time, the wolves began to look like dogs and they became people’s pets.

What a dog looks like

Dogs come in different sizes, colors and shapes, but they’re the same in some ways. All kinds of dogs have a set of forty-two strong teeth for eating. They have sharp claws (利爪) at the end of their feet for digging up soil (挖土) and holding onto the ground when they walk. They have very good eyesight. They also have high ability (能力) to hear and smell.

How a dog grows

A mother dog gives birth to one to twelve babies at a time. New-born baby dogs cannot see or hear until they are two weeks old. The mother dog gives the baby dogs milk. When they are four weeks old, they start eating soft food. When they’re eight weeks, the baby dogs have very strong legs and they can go for long walks.

How to read a dog’s feelings

Dogs act differently when they have different feelings. When a dog is angry, it opens its mouth and shows its teeth. When a dog is frightened, it lowers its ears and holds its tail (尾巴) between its legs. A happy dog always wags (摇摆) its tail.

根据短文内容,选择最佳答案。(10分)

小题1:People have started keeping dogs as pets since    .

A.there were humans

B.15,000 years ago

C.there were wolves

D.the wolves looked like dogs小题2:What can the sharp claws of dogs be used for according to the passage?

A.Climbing a tree.

B.Looking for food.

C.Digging up soil.

D.Fighting against other animals.小题3:When does a dog start to eat soft food?

A.When it’s 2 weeks old.

B.When it’s one month old.

C.When it’s 2 months old.

D.When it’s 8 months old.小题4:What does a dog do when it is frightened?

A.It opens its mouth.

B.It shows its teeth.

C.It wags its tail.

D.It holds its tail between its legs.小题5:What does the passage mainly tell us?

A.Some facts about dogs.

B.The history of dogs.

C.Something interesting about dogs.

D.Dogs are human beings’ friends.

题型:填空题

梯形图如图4-5-1所示,该梯形图示支持的诊断是()。

A.窦性心律,正常心电图

B.房性心律

C.交界性心律

D.窦性心律不齐

E.一度房室传导阻滞

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紫外线硫化氢分析仪的组成包括()、微处理器电子控制系统、采样系统组件、软件组态系统.

A.热交换器

B.色谱柱

C.光学分析系统

D.光源

题型:填空题

为了提高阀门阀杆表面耐腐蚀、耐擦伤性能,对其表面应进行()。

题型:填空题

下列有关股票与债券的区别,观点正确的是()

A.发行股票是为了筹措资金,发行债券是为了平衡财政收支

B.股票具有风险性,债券则没有风险性

C.股票买卖有时间限制,债券可以随时还本付息

D.股票以取得股息和红利为补偿条件,债券以定期收取利息为条件

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