下列各项，肾精亏虚所致头晕的表现是（）。
A.头晕目赤
B.头晕耳鸣
C.头晕目眩
D.头晕且沉
E.头晕刺痛
参考答案：B
_______ has recently been done to provide more buses for the people, a shortage of public vehicles remains a serious problem.
A．What
B．Though what
C．In spite of what
D．However what
下列离子反应方程式正确的是（ ）
A．金属钠投入蒸馏水2Na+2H2O=2Na++20H-+H2↑
B．向亚硫酸钠溶液中加入足量硝酸S032-+2H+=S02↑+H2O
C．用浓盐酸与Mn02反应制取少量氯气Mn02+4H++2Cl-=Mn2++2H2O+Cl2↑
D．硫酸亚铁溶液中加入酸化的双氧水Fe2++2H++H202=Fe3++2H2O
