2.
\((I)\) 观察下列各式的特点:
\( \sqrt {2}-1 > \sqrt {3}- \sqrt {2}\)
\( \sqrt {3}- \sqrt {2} > 2- \sqrt {3}\)
\(2- \sqrt {3} > \sqrt {5}-2\)
\( \sqrt {5}-2 > \sqrt {6}- \sqrt {5}\)
\(…\)
根据以上规律可知:\( \sqrt {2017}- \sqrt {2016}\) ______ \( \sqrt {2018}- \sqrt {2017}(\)填“\( > \)”“\( < \)”或“\(=\)”\()\).
\((2)\)观察下列式子的化简过程:
\(\left.\begin{matrix}\dfrac {1}{ \sqrt {2}+1}= \dfrac { \sqrt {2}-1}{( \sqrt {2}+1)( \sqrt {2}-1)}= \sqrt {2}-1, \\ \dfrac {1}{ \sqrt {3}+ \sqrt {2}}= \dfrac { \sqrt {3}- \sqrt {2}}{( \sqrt {3}+ \sqrt {2})( \sqrt {3}- \sqrt {2})}= \sqrt {3}- \sqrt {2}, \\ \dfrac {1}{ \sqrt {4}+ \sqrt {3}}= \dfrac { \sqrt {4}- \sqrt {3}}{( \sqrt {4}+ \sqrt {3})( \sqrt {4}- \sqrt {3})}= \sqrt {4}- \sqrt {3,}\end{matrix}\right.\)
\(…\)
根据观察,请写出式子\( \dfrac {1}{ \sqrt {n}+ \sqrt {n-1}}(n\geqslant 2)\)的化简过程.
\((3)\)根据上面\((1)(2)\)得出的规律计算下面的算式:\(| \dfrac {1}{ \sqrt {2}+1}- \dfrac {1}{ \sqrt {3}+ \sqrt {2}}|+| \dfrac {1}{ \sqrt {3}+ \sqrt {2}}- \dfrac {1}{ \sqrt {4}+ \sqrt {3}}|+| \dfrac {1}{ \sqrt {4}+ \sqrt {3}}- \dfrac {1}{ \sqrt {5}+ \sqrt {4}}|+…+| \dfrac {1}{ \sqrt {100}+ \sqrt {99}}- \dfrac {1}{ \sqrt {101}+ \sqrt {100}}|\).