Shipping putting in or leaving a port needs tugboat to tow . because putting in or leaving a port is a stochastic and discrete matter ( shipping " s size , load and the time of putting in or leaving a port are all stochastic ) , there is definite difficulty in tugboat ' s marshaling 在港口，船舶进出港需要拖轮拖引，由于船舶的进出是一个离散随机事件(船舶大小、载重吨及进出港时间均是随机的) ，因此为拖轮船队的合理配置带来一定的难度。
After alfred nobel economics price was granted to tow economist on researching information economics in 1996 , economist in the whole are more and more interested in information economics . and economists combine information economics theory with researching on venture capital function mechanism continually 随着1996年诺贝尔经济学奖授予维克里和莫尔斯两位信息经济学家，国内外学者愈来愈感兴趣于信息经济学，并且不断地将信息经济学理论运用于创业投资运行机制问题的研究。
Have put forward the schemes of five kinds of setting - up models by analysis to towed flight , concrete course and basic theories of scheme carry on the simple narration on each , compare their pluses and minuses . combine with study the purpose , the suitable method towed systematic modeling way is chosen 通过对牵引飞行过程的分析，提出了五种建立模型的方案，就每种方案的基本理论以及建模过程进行简单的叙述，对它们的优缺点进行比较，结合研究目的选择出适合的方法作为牵引系统的建模方式。
Dont let the balcony , the bathroom , the kitchen and so on place the overflow water get wet the floor , when clean the floor , as far as possible use the dry rag to tow along the floor direction scratches , do not let the water flow underside of the floor from the commissure of the floor , avoiding the moisture content sharp increased 切勿水泡。不可让阳台浴室厨房等处溢出的水弄湿地板，在清洁地板时，尽量用捻干的抹布顺地板方向拖擦，勿让水从地板逢中流入地板下面，避免含水率剧增。
