当铜块的中心嵌入一块铁以后，铜的密度是不变的．______．_爱下问搜题

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问题问答题

当铜块的中心嵌入一块铁以后，铜的密度是不变的．______．

答案

因密度是一个常量，同种物质的密度相同，不随体积、质量、形状的变化而变化，所以铜块的中心嵌入一块铁，铜的密度是不变的．

故答案为：√．

阅读理解

Directions: Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need. 9’

A. conveyed B. stand C. oral D. disagreement AB. guide AC. internationally
AD. raised BC. accomplished BD. intentionally CD. expression

Ever since humans have lived on the earth, they have made use of various forms of communication. Generally, this expression of thoughts and feelings has been in the form of ___小题1:___speech. When there is a language barrier, communication is ___小题2:___through sign language in which motions___小题3:___ for letters, words, and ideas. Tourists and the people unable to hear or speak have had to turn to this form of ___小题4:___. Many of these symbols of whole words are very lively and exact and can be used ___小题5:___; spelling, however, cannot.
Body language sends ideas or thoughts by certain actions, either___小题6:___ or not. A wink can be a way of showing that the party is only joking. A nod means approval, while shaking the head indicates ___小题7:___.
　　Other forms of nonlinguistic language can be found in Braille (a system of ___小题8:___ dots read with the fingertips), signal flags, Morse code, and smoke signals. Road maps and picture signs also ___小题9:___and warn people. While language is the most common form of communication, other systems and techniques also express human thoughts and feelings.

问答题简答题

试述行为主义人格观点的贡献？