【简答题】It may not be news to parents of age girls, but researchers have confirmed that no one can stop their 16-year-old daughter from deciding how the family spends its money. The willpower and determin...
【单选题】在强酸性或强碱性溶液中都能大量共存的一组离子是 ( )
A.
A. Ba 2+ , Fe 3+ , Br - , NO 3 -
B.
B.Na + ,Ca 2+ ,HCO 3 - ,NO 3 -
C.
C.Al 3+ ,NH 4 + ,SO 4 2- ,Na +
D.
D. Na + , K + , NO 3 - , SO 4 2-
【单选题】内蒙古自治区稀土查明资源储量居世界首位。()是世界上最大的稀土矿山。
【简答题】Women are a force for change in Australian society. The pride of place given to men as almost the sole shapers of Australian history is being challenged. Today husbands more often than no share househ...
【单选题】下列选项中,正确的是( )
A.
向Ba(OH) 2 溶液中滴加NH 4 HSO 4 溶液至刚好沉淀完全:Ba 2+ +2OH - + N H +4 +H + + S O 2-4 =BaSO 4 ↓+NH 3 ?H 2 O+H 2 O
B.
在强碱性溶液中能大量共存的离子组是:Na + 、Ba 2+ 、 HC O -3 、Cl -
C.
1.5molNO 2 与足量H 2 O反应,转移的电子数为1.5N A (N A 为阿伏加德罗常数的数值)
D.
与强酸、强碱都能反应的物质种类只有两性氧化物或两性氧氧化物
【单选题】We may conclude that the country being discussed is not the United States ______.
A.
because expenditures for food declined
B.
from the statement that the saturation point was rapidly being approached for first household radios
C.
because no mention is made of military expenditures
D.
because the people were affluent