问题 填空题

小明是个摄影谜,有一天他向全班同学展示了他拍摄的一张金鱼照,如图所示.但小明告诉同学们说瓶中只养了一条鱼!你认为小明的金鱼照一定______伪造的(选填“是”或“不是”),你这样判断的依据是______.

答案

(1)拍摄到的第一条鱼,不是鱼的实际位置,而是逆着折射光线看到了鱼的虚像,所以虚像比鱼的实际位置浅一些;所以①是伪造的.

(2)拍摄到的第二条鱼是当从鱼缸侧面看水中鱼时,这时鱼缸的左侧部分相当于一个凸透镜,由凸透镜成像的规律知,鱼在1倍焦距以内成正立放大的虚像.

所以小明的金鱼照一定是伪造的,判断的依据是经水面和鱼缸侧壁(凸透镜)折射各成一个像.

故答案为:是;经水面和鱼缸侧壁(凸透镜)折射各成一个像.

多项选择题
阅读理解

阅读理解。

                                                         The Cost of Higher Education

     Individuals (个人) should pay for their higher education.

     A university education is of huge and direct benefit to the individual. Graduates earn more than non-

graduates. Meanwhile, social mobility is ever more dependent on having a degree. However, only some

people have it. So the individual, not the taxpayers, should pay for it. There are pressing calls on the

resources (资源) of the government. Using taxpayers' money to help a small number of people to earn

high incomes in the future is not one of them.

     Full government funding (资助) is not very good for universities. Adam Smith worked in a Scottish

university whose teachers lived off student fees. He knew and looked down upon 18th-century Oxford,

where the academics lived comfortably off the income received from the government. Guaranteed salaries,

Smith argued, were the enemy of hard work; and when the academics were lazy and incompetent, the

students were similarly lazy.

     If students have to pay for their education, they not only work harder, but also demand more from

their teachers. And their teachers have to keep them satisfied. If that means taking teaching seriously,

and giving less time to their own research interests, that is surely something to celebrate.

     Many people believe that higher education should be free because it is good for the economy (经济).

Many graduates clearly do contribute to national wealth, but so do all the businesses that invest (投资)

and create jobs. If you believe that the government should pay for higher education because graduates

are economically productive, you should also believe that the government should pay part of business

costs. Anyone promising to create jobs should receive a gift of capital from the government to invest.

Therefore, it is the individual, not the government, who should pay for their university education.

1. The underlined word "them" in Paragraph 2 refers to _____.[ ]

A. taxpayers

B. pressing calls

C. college graduates

D. government resources

2. The author thinks that with full government funding _____.[ ]

A. teachers are less satisfied

B. students are more demanding

C. students will become more competent

D. teachers will spend less time on teaching

3. The author mentions businesses in Paragraph 5 in order to _____.[ ]

A. argue against free university education

B. call on them to finance students' studies

C. encourage graduates to go into business

D. show their contribution to higher education