元组变量t=("cat","dog","tiger","human")，t[::–1]的结果是('human','tiger','dog','cat')‪‪‪‪‪‪‫‪‪‪‪‪‫‪‪‪‪‪‫‪‪‪‪‪‫‪‪‪‪‪‪‫‪