问题如下：
What role does the alternative hypothesis play when testing a hypothesis?
选项：
解释：
The alternative specifies the range of values where the null should be rejected. In most tests, the alternative is the natural complement to the null, although this does not have to be the case. It is possible to specify a test where neither the null nor the alternative is true.
什么情况下备择假设不是原假设的对立面
