听力原文： Today I will continue my discussion of. the behaviorist school of psychology, a

nd tell you what I feel about some problems related to behaviorism. The psychologist wishes to know human behavior. and human mind. He or she must therefore design methods of investigating human beings when they actually live. The behaviorist school of psychology, however, has done almost all of its studies under laboratory conditions. Behaviorism seems to want the respectability Of natural science, but it uses the methods of fifty years ago. Moreover, behaviorist studies often do not make any great contributions, but the author will cover this up with mathematical tables and statistics which are not important for the study. To investigate human behavior. in a more natural setting is difficult, I admit. Nevertheless, there are at least two ways to conduct such a task.

According to the speaker, what are the problems related to behaviorism？

A．The behaviorist school of psychology has done its studies under laboratory conditions.

B．Behaviorism uses the update methods.

C．Mathematical tables and statistics are not very useful.

D．All of the above.