问题 问答题

小明在“探究光的反射规律”的实验时,把测量的数据记录在下面的表格里.

(1)请你帮他将表格补充完整.

实验次数入射角反射角
130°______
2______45°
375°______
(2)根据数据,你发现的光的反射规律是______.

答案

(1)发生反射时,反射角与入射角相等,因此当入射角为30°时,反射角也为30°;当反射角为45°时,折射角也为45°;当入射角为75°时,反射角也为75°.

(2)从表中的数据可得,反射角随入射角的增大而增大.

故答案为:(1)30°;45°;75°;(2)反射角随入射角的增大而增大.

单项选择题


Directions: There are 10 blanks in the following passage. For each numbered blank, there are 4 choices marked A, B, C and D.

It is difficult to imagine what life would be like without memory. The meanings of thousands of everyday perceptions, the bases (51) the decisions we make, and the roots of our habits and skills are to be (52) in our past experiences, which are brought into the present (53) memory.
Memory can be defined as the capacity to keep (54) available for later use. It includes not only "remembering" things like arithmetic or historical facts, but also any change in the way an animal typically behaves. Memory is (55) when a rat gives up eating grain because he has sniffed something suspicious in the grain pile. Memory is also involved when a six-year-old child learns to swing a baseball bat.
Memory (56) not only in humans and animals but also in some physical objects and machines. Computers, for example, contain devices for storing data for later use. It is interesting to compare the memory-storage capacity of a computer (57) that of a human being. The in stant-access memory of a large computer may hold up to 100 000 "words" —ready for (58) use. An average American teenager probably recognizes the meanings of about 100 000 words of English. However, this is but a fraction of the total (59) of information which the teenager has stored. Consider, for example, the number of facts and places that the teenager can recognize on sight. The use of words is the basis of the advanced problem-solving intelligence of human beings. A large part of a person’s memory is in terms of words and (60) of words.

A.by

B.from

C.with

D.in

单项选择题