請問這句話是什么意思？

1. if作為“是否”的用法初二課本暫時沒有涉及，只作拓展之用。
2. 以下內(nèi)容只作了解，現(xiàn)行牛津初中教材內(nèi)容已經(jīng)刪除。
在表示某一情形總會出現(xiàn)相同的結(jié)果時，if從句和主句都用一般現(xiàn)在時。
If the engine gets too hot, it starts to smoke. 發(fā)動機過熱就會開始冒煙。
3. if在虛擬語氣中的用法為高中內(nèi)容，比較復(fù)雜，在此不作涉及。

◇課本例句
1. If you eat my food, I won’t talk to you. (P58)
2. If I don’t have food, I will die. (P58)
3. If I don’t have food, I will die too. If I die, no one will look after you. (P58)
4. If hunters catch a giant panda, they will kill it for its fur. (P60)
5. If farmers cut down trees and forests, giant pandas will have nowhere to live. (P60)
6. If people find baby pandas alone, they will often take them away. (P60)
7. If we do nothing, soon there will be no giant pandas in the world! (P60)