[00:03.88]Module4 A SCIENCE EXPERIMENT
[00:08.38]UNIT1 You must stir it gently.
[00:13.36]1 Listen and read.Then say
[00:19.41]Class,we're going to carry out
[00:22.07]a chemical experiment today.
[00:24.95]Now,do you have everything you need?
[00:28.38]Yes,we've got an eye-dropper,a coin,
[00:32.39]some liquid soap and a glass of water.Good
[00:38.33]Now,there are two parts to this experiment
[00:42.61]Zhang Hai,I want you to see how many drops
[00:46.29]of water you can fit on the surface of the coin
[00:51.17]Take the eye-dropper and put it into the glass
[00:54.99]of water.Fill the eye-dropper with water,
[00:59.42]then carefully squeeze the drops onto the coin
[01:04.20]You must be careful when you're doing this.
[01:07.41]You mustn't spill any water over the side
[01:09.88]of the coin.Right.Here I go.
[01:15.48]How many drops of water could you get
[01:17.93]on the coin?Five.
[01:20.58]Good.Now,add some liquid soap to the water
[01:25.64]You shouldn't put too much in.
[01:28.08]Just a little will do...that's right.
[01:32.17]Now,you must stir the soapy water gently.
[01:36.50]Next,take the eye-dropper,
[01:39.47]fill it with the soapy water
[01:42.04]and see how many drops
[01:43.69]you can fit onto the coin.OK..Let me count..
[01:48.45]One,two,three,four,five,six,seven,eight,
[01:53.65]nine drops!Good!Can anyone tell me
[01:58.46]why Zhang Hai could fit more soapy drops
[02:01.28]on the coin?
[02:04.10]Soapy drops are smaller than water drops,
[02:08.44]so more soapy drops could fit onto the coin
[02:13.03]Excellent answer,Feifei!
[02:14.42]