Do you often go to work on _____________? [ ]
A. Monday
B. monday
C. Mondays
D. mondays
答案:C
除去CO中混有的CO2应采用的方法是 [ ]
A.用燃着的木条点燃
B.通过灼热的氧化铜
C.通过澄清的石灰水
D.通过红热的铁丝