— ________ tea would you like?
— Two cups. [ ]
A. How many
B. How much
C. What
D. Which
答案:B
将51.2gCu完全溶于适量浓硝酸中,收集到氮的氧化物(含NO、N2O4,NO2)的混合物共0.8mol,这些气体恰好能被500mL 2mol/L NaOH溶液完全吸收,发生的反应为:2NO2+2NaOH=NaNO2+NaNO3+H2O,NO+NO2+2NaOH=2NaNO2+H2O则生成的盐溶液中NaNO3的物质的量为( )
A.0.4mol
B.0.2mol
C.0.6mol
D.0.8mol
二尖瓣换瓣指征为
A.左房压明显升高
B.瓣膜钙化
C.左室舒张末压明显升高
D.心功能Ⅲ级
E.年龄小于30岁