题目

下列说法正确的是（） A . 泊松亮斑是指用光穿过不透明的圆盘中心小孔时在阴影的中心出现一个亮斑 B . 在双缝干涉实验中，同等条件下用红光做实验比用紫光做实验得到的条纹间距更小 C . 拍摄玻璃橱窗内的物品时，在镜头前加一个偏振片可以减弱玻璃表面反射光的影响 D . 根据多普勒效应可以测量出其他星系向着还是远离地球运动的速率在下面短文的空格内填入适当的词，使其内容通顺，每空格限填一词，首字母已给出。 　　Often, doctors tell some people to go on diets (节食). The doctors hope the diets will make the people feel b________. They hope the diets will make the people healthy. 　　Alana was on a diet, b________ she didn't like it at all. She was not allowed to eat her favourite food by the doctor. While her brother Frank ate chocolate, she had to eat an apple. Alana was on the diet f________ two months. Her doctor was pleased with her.“You have been very good.” he said, “You can eat some of the f________ you like best. But only a little. Don't eat too m________ sweets. Don't eat too much ice cream. If you do, you will get a lot of weight a________” 　　Then the doctor put Frank on a diet. It was a different kind of diet. “You c________ eat chicken or eggs. Frank,” said the doctor.“These foods will make you in trouble.” 　　“How long will I have to be on the diet?” asked Frank. 　　“A long time.” answered the doctor, “Maybe for the r________ of your life.” 　　“But I really like chicken.” said Frank.“You said it is one of the best meat to eat.” 　　“It is a very good food for most people,”said the doctor.“But when you eat it, it makes you sick. It is not good food for you.” 　　“You're right,”said Frank.“Well, I'll eat more cake instead.”