1、In theory 和 In practice 的区别：
In theory: Use “in theory” when you want to refer to something that may not be true or realized in real situations.
For example, "In theory, a rural education system exists, but in practice, there are few teachers to teach."
2、词语替代
more--greater, thus--therefore, some--several, besides--in addition, kind--type, be concluded as--be concluded to be, whole--entire, in contrast--conversely or (On the contrary) (相反地), Except of--Excepting, Assuming that--Assume that, enough--sufficiently, Then--Next, n't--not, indifferent--equivalent, hard--difficult, mean--indicate, whether or not--whether, about--approximately, Nowadays--Currently.
term--contract, be considered as-- be solved by analogy to, solution--approach, must--should, incur--achieve,
学会用Note that, determined(确定的), aims to, More specifically(更具体地说), the presence of (...的存在), The instance we take for example,
句中的 which 换成 that 。
我们的工作用study。
3、标点
Then--Then, 注意then之后要加逗号。
i.e.--i.e., 注意i.e.之后要加逗号。
and 前要注意视情况加逗号。
4、公式表示用 Eq. (1) 或 Eqs. (1) and (2) 。
5、$+$---$\!+\!$：加号前后要加上\! ，来去掉加号前后的空格，减号也是如此。对于* /，一般不加，因为乘除符号本身就占的位置少，加上之后可能会使公式变得很挤，影响排版效果。
6、实验部分要用过去时。
7、As discussed in Section III, 注意section首字母要大写。