【单选题】An account usually shows four kinds of amounts in a specific accounting period, namely the beginning balance, increase sum, decrease sum and ending balance. The relationship among them is shown as ( ...
A.
Ending balance = beginning balance - increase sum + decrease sum
B.
Ending balance = beginning balance + increase sum + decrease sum
C.
Ending balance = beginning balance increase sum - decrease sum
D.
Ending balance = beginning balance + increase sum - decrease sum
【简答题】铝是国民经济发展的重要材料,铝在地壳中的含量约占8%,目前我国铝消费量超过430万吨,在众多的金属中仅次于铁.请回答下问题: (I )实验室中用金属铝制备少量氢氧化铝,有以下3种方案: 方案1:Al H 2 S O 4 Al 3+ NaOH Al(OH) 3 ; 方案2:Al NaOH AlO -2 H 2 S O 4 Al(OH) 3 ; 方案3: Al H 2 SO 4 Al 2 (SO 4 ...