如果结果不匹配，请 
更多“通span喷嘴不需要的工具（)。”相关的问题
判断下列函数的奇偶性．
(1)
(2)
(3)＜span name='maths'＞f(x)=\frac{x\sinx}{\cosx}＜/span＞]
A．increase
B．expansion
C．growth
D．prolongation
A precisely B instantly C initially D exclusively
The second research proved that
A．the life span of trees in the Amazon basin is much longer than others.
B．trees consume carbon dioxide until they die.
C．it takes hundreds of years for trees to purify atmosphere.
D．the carbon that trees consumed may return to the atmosphere in five years.
设H为Hilbert空间，{un}为H的无穷标准正交基，对n=1，2，…，设Fn=span{u1，u2，…un}。若Pn为从H到F，，的正交投影．求证：
(a)任每一x∈H有Pnx→x。
(b)‖Pn-I‖不收敛到0。
A.在结构的选择上，环境因素的多维性通常被忽略
B.结构仅仅确定了一种静态的角色、责任和关系
C.越来越多的管理者意识到，对于战略变革，正式结构是一种有力却迟钝的工具
D.企业很容易达到结构匹配
A) The penny which doubles itself every day for one month.
B) The time span of at least two million years in human history.
C) An illustration of the exponential growth rate given by the author.
D) The large amount of money you would luckily make after the fourth week.
