下表中列出了一些物質(zhì)的熔點和沸點（1標準大氣圧下），根據(jù)表中數(shù)據(jù)回答下列問題：

物質(zhì)	熔點（℃）	沸點（℃）
水	0	100
萘	80	210
水銀	-39	357
酒精	-117	78
氮	-210	-196
氧	-268	-183

（1）表中所列物質(zhì)在常溫下屬于固態(tài)的是________；氧在-145℃時所處的狀態(tài)是______
（2）要探究萘的熔化和沸騰過程中溫度的變化，應選_______作溫度計的測量物質(zhì)。
（3）如果在1標準大氣壓下用降溫的辦法從空氣中提取氧和氮，那么溫度下降時首先液化被分離出來的是                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  （4）1標準大氣圧下，當溫度為0℃時，水的狀態(tài)（  ）
A．一定是固態(tài)    　       B．一定是液態(tài)    　 
C．一定是固液共存態(tài)      　D．以上三種狀態(tài)都有可能