[引导状语从句和表语从句]
Many exam candidates lose marks simply because they do not read the questions properly.
许多应试者失分只是因为没有好好地读题。
They say this is because when you laugh, your brain sends chemicals around your body that are good for you.
他们说这是因为，笑的时候大脑会向全身发送有益的化学物质。
There are many homeless people because of the earthquake.
因为地震，很多人无家可归。