最后，总统收到法案时的第四个选择是口袋否决。

Finally, the president's fourth option when he receives a bill is a pocket veto.

在这种情况下，如果总统没有签署该法案，它不能自动成为法律，而是通过口袋否决自动否决了它。

In this situation, if the president does not sign the bill, it does not automatically become a law, but instead is automatically vetoed through a pocket veto.