“歼20”是我国自主研制的新一代隐身重型歼击机，具有卓越的机动_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

“歼20”是我国自主研制的新一代隐身重型歼击机，具有卓越的机动性能，当它在空中加速向下俯冲的过程中，动能，重力势能．（选填“增大”、“不变”或“减小”）

答案

增大；减小．

题目分析：“歼20”在空中加速向下俯冲时，质量不变，速度不断增大，动能增大．高度不断减小，重力势能不断减小．

完形填空

完形填空（共20小题;每小题1.5分,满分30分）
阅读下面短文,从短文后各题所给的四个选项（A、B、C、和D)中，选出可以填入空白处
的最佳选项，并标在答题卷的相应位置。用答题卡的考生，先把选出的最佳选项标在试卷的
相应位置，再转涂到答题卡上。
Today’ s English learner has a wide choice of dictionaries. There are ______36 with AmericanEnglish, with British English, with idioms or slang, and 37 with pictures. One of the most 38______dictionaries I have seen among many students is the 39______ electronic dictionary. All you have to do is to ______40 a word in your language and you can see it and 41______ it in English. That* s great, right? Well, I think it* s great, too…but only sometimes.
Bilingual electronic dictiooaries are fast and ______42 . They can be great 43 you are traveling and need information quickly. 44______ I am against electronic dictionaries and even bilingual 45______dictionaries in many cases. Let me explain.
When you reach an intermediate(中等的）level of English, you know 46 ______of the language to ask the meaning of certain things while using English. Translating between languages in your head ______47 time. You should be translating as little as possible and 48 ______in English as much as possible. I strongly recommend that intermediate and advanced students should 49 ______an English-English dictionary that is made ______50 for your understanding. For example，Foreign Language Teaching and Research Press has good dictionaries for students and 51______ publishing houses do, too.
I also feel that paper dictionaries are better for studying than electronic dictionaries. True,

they take longer to use. But, for some reason, the information you______ 52 seems to stay in your head longer. It may be______ 53 you are forced to spell the word in your head and therefore "see it" more clearly in your ______54 .
So what do you do if you have checked an English - English dictionary and still don ’ t understand something? Go to your bilingual dictionary. It is useful sometimes. Just remember to
try to ___55 in English a s much as possible.
小题1:

A． dictionaries

A． interesting

B． get across

D． reflecting

A． especially

填空题

dBm是用于表示功率的单位，0dBm相当于（）.，计算公式为：（）.