Though he is at home, he doesn't feel for he has many things to do.
A:alone; lonely
B:lonely; alone
C:alone; alone
D:lonely; lonely
观察下列关于自然数的等式:
a1:32-12=8×1;
a2:52-32=8×2;
a3:72-52=8×3
根据上述规律解决下列问题:
明清两朝的皇帝住在( )