鸡心碗
参考答案：
明永、宣两朝烧制。碗底心有鸡心样突起，腹深足小。常见大小二种。永乐碗胎体轻，足矮；宣德时则足高、胎厚。
下列说法正确的是 （ ）
A．pH＝5的NH4Cl溶液或醋酸中，由水电离出的c(H+)均为
10－9 mol/L
B．pH＝3的醋酸和pH＝11的NaOH溶液等体积混合后，pH＞7
C．在c(H+)∶c(OH－)＝1∶1012的溶液中，Na+、I－、NO3－、SO42－能大量共存
D．0.1 mol/L Na2CO3溶液和0.1 mol/L NaHSO4溶液等体积混合，溶液中c(Na+)+c(H+)＝c(CO32－)+c(SO42－)+c(HCO3－)+c(OH－)
Which of the following statements about stock valuation is least likely correct（）
A. If estimated value ＜ the market price, buy the stock : it's under priced.
B. If the expected rate of return ＞ the required rate, buy the stock; it's under priced.
C. If the expected rate of return ＜ the required rate, don't buy the stock; it's under priced.
