history可数吗

　　例句：

　　I have a history class at 9 o'clock.

　　我9点钟有历史课。

　　It was the study of history that gave birth to the social sciences.

　　对历史的研究孕育了社会科学。

　　I loved history when I was at school.

　　我上学时喜欢历史。