句子变复数首先是名词变成复数,然后相应的数量词、动词、代词等也要跟着变,本句中的名词是strawberry,其复数形式是变y为i,加es,所以是:strawberries;然后修饰strawberries的数词a要去掉;前面的动词is也要变成复数形式,即are;this也需要变成thers。所以句子应该是:
These are red strawberries.
these are red strawberries.
These are red strawberries.
These are many strawberries.