After analyze each straightening process,structural feature,equipment composition and property of the two kinds of aluminum rod guide,the conclusion is that Ⅱ straightener (is used in Pingguo Aluminum Plant) is more advantageous than Ⅰ straightener (is used in Guizhou Aluminum Smelter

) to the number of American (Chinese) outbound tourists with natural trend curve, ideal curve Ⅰ and ideal curve Ⅱ, it is found that the concave valley occurs apparently when the crisis event happens.

For typeⅠ、 typeⅡ and type O Crank-rocker mechanisms,an important Proposition,four exceptive instances and their proofs of the longest lever are proposed,which will help us to understand the property of the crank and rocker mechanism deeply.