下列物质的名称、俗名与化学式完全对应的是 ( )
A:氢氧化钙熟石灰 CaO
B:氢氧化钠纯碱 NaOH
C:乙醇酒精 C2H5OOH
D:汞水银 Hg
We work during the week, but weekends and evenings are usually____.
All the doctor’s efforts were________and the man involved in the car accident soon died.