你好,同學(xué)

class屬于集體名詞,某些集體名詞,如family, team等作主語時,如果作為一個整體看待,謂語動詞用單數(shù)形式,如果就其中一個個成員而言,謂語動詞用復(fù)數(shù)形式.如：
His family is a happy one.
The whole family are watching TV.
這類名詞有：audience,class,club,company,crew,enemy,crowd,government,group,party,public,team等.
所以,后面用has還是have, 要視情況而定.如果作為一個整體看待,后面用has,如果強調(diào)其中一個個學(xué)生,后面用have, 如：

Our class has a big blackboard. 我們班有一塊大黑板.

All our class have a class meeting on Tuesdays.每逢周二,我們班都開班會.



希望能幫到你,祝更上一層樓O(∩_∩)O
有不明白的請繼續(xù)追問(*^__^*)