河北加拿大版初中英语--UNIT 4

UNIT 4
[00:03.08]Lessons 25~32
[00:08.05]Look into Science!
[00:11.89]Lesson 25:
[00:16.64]Keep the Candle Burning!Science is so interesting!
[00:23.72]I'm sure you'll like this experiment!
[00:28.68]When you do this experiment,you will learn something about air!
[00:34.64]What do you need?
[00:37.80]a candle
[00:40.67]a candleholder
[00:44.02]a big glass jar
[00:48.14]a shallow² dish with water
[00:52.58]matches
[00:55.43]To make a candle burn,you "light" it. What do you use?
[01:02.56]A match.What do you do?
[01:07.89]1.Put the candle in the candleholder.
[01:14.14]2.Put the candle- holder¹ in the dish
[01:20.38]3.Fill the dish half full of water.
[01:26.86]4.Light the candle.
[01:31.61]5.Let the candle burn for two or three minutes.
[01:39.47]6.Carefully put the jar over the candle.
[01:46.74]7.Look at the water in the jar.What observation³ can you make?
[01:56.72]What is happening?
[02:00.06]As the candle burns,it uses up oxygen in the air.
[02:06.90]When the candle stops burning it has used up all the oxygen in the air.
[02:16.05]The water inside the jar then rises.
[02:22.11]How far did the water rise?Air is about one- fifth oxygen,
[02:30.36]so the water rises and fills about one- fifth of the jar.
 

1 holder   

n.持有者，占有者；(台，架等)支持物

参考例句：

• The holder of the office of chairman is reponsible for arranging meetings.担任主席职位的人负责安排会议。
• That runner is the holder of the world record for the hundred-yard dash.那位运动员是一百码赛跑世界纪录的保持者。

2 shallow   

adj.浅的，肤浅的，浅显易懂的；n.(pl.)浅滩，浅处；v.变浅

参考例句：

• The dish is too shallow to serve soup in.盘子太浅，盛不了汤。
• His analysis was always shallow.他的分析总是很肤浅的。

3 observation   

n.观察， 观测， 观察资料（或报告）

参考例句：

• The new breed is under observation.新品种正在观察中。
• Did you keep him under observation?你对他进行监视了吗？