【单选题】小组正在开发一个电费计费系统,系统中包含上百万电费数据,调试时,发现执行查询时,每次返回所有数据,非常费时。最好的处理方法是( )。
【单选题】When interest rates rise:
A.
the cost of investing rises, and businesses buy less equipment and structures.
B.
the return on investments rises also, and businesses eager to lock in future profits increase their investments.
C.
consumers are encouraged to save, and the automatic relationship between savings and investment leads to an increase in investment.
D.
investment tax credits kick in to maintain a steady level of investment.
【简答题】已知|x|=5,y=3,则x-y=______.
【简答题】已知x:y=3:2,则(x+y):y=______.
【简答题】短歌行作者是谁,文学史上的“三曹”指的是哪三个人?“三苏”又指的是哪三个人?
【单选题】土的天然含水量,反映了土的干湿程度,按下式( )计算
【简答题】When interest rates fall, the price of a callable bond will: A.rise more than an option-free bond. B.rise less than an option-free bond. C.fall less than an option-free bond.