Prevention of Aids should be taught routinely in universities because of the effects ______ can have on keeping students from being infected with Aids.
A．it B．that C．which D．one
A
【详解】
考查代词。句意：预防艾滋病的知识应定期在大学教授，因为这可能对防止学生感染艾滋病产生影响。当that在定语从句中做宾语时可以省略，所以可以判断空格应该填it指代主句主语“Prevention of Aids”，恢复句子是“because of the effects that it can have on keeping students from being infected with Aids”。故选A。
【点睛】
在定语从句中，that充当主语时不可省略，但作为宾语时可以省略。在这道题中定语从句的宾语that省略了，所以可以判断空格应该填it指代主句主语“Prevention of Aids”，恢复句子是“because of the effects that it can have on keeping students from being infected with Aids”。故选A。