he lives in a large flat and owns much money, he doesn’t seem as happy as before．
A. Before
B. Whether
C. Unless
D. While
网友回答
A. Before
B. Whether
C. Unless
(答案→)D. While
解析：连词辨析。A．在……以前B．是否；不论 C．除非 D．当……时候；虽然；然而。句意：虽然他住在一所大公寓里并且有很多钱，但是他好像不如以前那么幸福了。故选D。