The emphasis on academic performance and the fear of controversy have prompted many schools to make only a half-hearted effort to teaching students about sex. The result: Puberty lesson periods are used to teach other subjects, and students are told to read the textbooks at home - that is, if there's a textbook at all.http://www.chinadaily.com.cn/china/2006-09/23/content_695298.htm
參考答案:at all 强调
如果有教科书的话