题目

14.请你阅读下面的文章：小丽在研究一定质量的气体的压强时，想到了这样一个问题：如果将这些气体的体积保持不变，它的压强会不会随着温度的变化而变化呢？针对这一问题，她经过思考，提出两种猜想：（l）这些气体在体积不变时，温度越高，压强越大；（2）这些气体在体积不变时，温度越高，压强越小。 图8    究竟哪一种猜想是正确的呢？小丽进行了如下的实验：    在烧瓶中封入一定质量的某种气体，烧瓶的一端连接在压强计上，将烧 Do you want to send a secret message? Here are two wonderful ways to do it!A lemon juice letterWhat will you need:A cup of lemon juiceA thin paintbrush(画笔)A piece of white paperA light1.Use the lemon juice to write a message on the paper. When it dries, you can’t see anything on the paper.2.Give your secret message to a friend or a family member.3.Ask the person receiving your letter to hold the paper near the light. The light will make the secret message show up! The lemon juice will turn brown.A mirror messageWhat will you need:A potatoA knifeA bathroom mirror1. Use a knife to peel(削皮)the potato.2. Use the potato to write a message on the bathroom mirror.3.Your message will be invisible until you take a bath. When you take a bath, close the door. The hot air with water will make your message show.Give someone else a surprise! Write a message on the bathroom mirror for a family member. See how long it takes the person to discover your secret message!【1】What makes the secret message in “a lemon juice letter” show up?______A.Air.B.Light.C.Fire.D.Water.【2】Which is TRUE about the lemon juice letter? ______A.Only children can make it.B.The words in the message must be yellow.C.The lemon juice is brown when you hold it near the light.D.You can’t see anything when it is wet.【3】What do NOT you need to make a mirror message? ______A.A piece of paper.B.A potato.C.A knife.D.A bathroom mirror.【4】What does the underlined word “invisible” mean? ______A.奉献的B.强大的C.清晰的D.看不见的【5】What is the main idea of the passage?______A.When to use a secret message.B.How to make a secret message.C.How to use lemon juice.D.How to clean a bathroom mirror.