青虫菌、杀螟杆菌都属于细菌性药剂。

未分类题某类产品n种品牌在某地区的市场占有率常用概率向量u=(u1，u2，…，un)表示(各分量分别表示各品牌的市场占有率，值非负，且总和为1)。市场占有率每隔一定时间的变化常用转移矩阵Pn×n表示。如果在相当长时期内，该转移矩阵的元素均是常数，又设初始时刻的市场占有率为向量u，则下一时刻的市场占有率就是uP，再下一时刻的市场占有率就是uP2，…，而且，市场占有率会逐步稳定到某个概率向量Z，即出现ZP=Z。这种稳定的市场占有率体现了转移矩阵的特征，与初始时刻的市场占有率无关。 假设占领某地区市场的冰箱品牌A与B，每月市场占有率的变化可用如下常数转移矩阵来描述：则冰箱品牌A与B在该地区最终将逐步稳定到市场占有率______。A.(1 4，3 4)B.(1 3，2 3)C.(1 2，1 2)D.(2 3，1 3)

单项选择题泵壳具有汇集液体和将部分动能转为静压能的作用 A、正确 B、错误

单项选择题中国茶文学的开山之作是什么 A、《僮约》 B、《荈赋》 C、《七碗茶歌》 D、《茶经》

未分类题A purchase plan for a stereo receiver requires 20 percent of the total cost as a down payment and monthly payments of $30.Column A Column BThe total cost of the stereo receiver $450A.if the quantity in Column A is greaterB.if the quantity in Column B is greaterC.if the two quantity are equalD.if the relationship cannot be determined from the information given

判断题票务运行中的现金包括备用金和售票的票款

未分类题The median of 10,15, x and y is 18. 5, and x < y.Column A Column BX 22A.if the quantity in Column A is greaterB.if the quantity in Column B is greaterC.if the two quantity are equalD.if the relationship cannot be determined from the information given

未分类题Each of the following numbers has two digits blotted out. Which of the numbers could be the number of hours in x days, where x is an integer?E.65■,■20

单项选择题“元”的甲骨文构形象一个站立的人，突出其头部。所以，元的本义是（ ） A．元气 B．人头 C．头发 D．上部 A、元气 B、人头 C、头发 D、上部

未分类题If a certain company purchased its computer terminals for a total of $540,400 and each of the terminals was purchased for $350, how many terminals did the company purchase?E.1264

未分类题What is the cost, in cents, of using a certain fax machine to send n pages of a report if the total cost for sending the first k pages is r cents and the cost for sending each additional page is s cents? (Assume that n>k. )A.r+s (n-k)B.r+s (n + k)C.rs (n + k)D.kr+s (n-k)E.kr+ns