测铁工作曲线时，工作曲线截距为负值原因可能是（）A、参比液缸_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

测铁工作曲线时，工作曲线截距为负值原因可能是（）

A、参比液缸比被测液缸透光度大

B、参比液缸与被测液缸吸光度相等

C、参比液缸比被测液缸吸光度小

D、参比液缸比被测液缸吸光度大

答案

参考答案：D

完形填空

We don’t have special skills but all of us can be special people. Why? Because we can volunteer.
Mary, a Canadian girl, was sad because she had a heart problem. Her classmates had always been trying to her up. However, they couldn’t because she was so that she needed lots of money to have an operation (手术）. Her parents to get help from the public. A TV station soon a call-in center for Mary. Many people called and offered to help Mary . At the same time, Mary’s classmates donated (捐赠）money, and some of them even handed out notices Mary’s story at a local supermarket. All above helped Mary a lot. Mary and her parents really everyone’s hard work.
There are lots of opportunities (机会) for us to volunteer. The Asian Games in Guangdong, for example, need volunteers. And volunteers are also in local hospitals, old people’s homes, and so on. We can also help homeless people and people, and volunteer to clean up parks. Volunteering is not only a great way to help people, but also a great way to make new friends, to learn new skills, and to have fun.

B．hundreds of

D．two hundreds

单项选择题

People often recall having felt chilled before the onset of a cold. This supports the hypothesis that colds are, at least sometimes, caused by becoming chilled; it is the chill that allows a rhino virus, if present, to infect a person. Which of the following, if true, most seriously weakens the force of the evidence cited above

A．Being chilled is a form of stress, and stress lowers the defenses of a person’s immune system, which guards against infection.

B．After a rhino virus has incubated in a person for several days, the first symptom it causes is a feeling of chilliness.

C．People who are tired and then become chilled are more likely to catch severe colds than are people who are chilled without being tired.

D．Some people who catch colds are not sure what it was that allowed them to catch cold.

E．(E) Rhino viruses are not always present in the environment, and so a person could become chilled without catching a cold.