3. 省略句使用频繁As already discussed 前已讨论As explained before 前已解释As described above 如上所述As previously mentioned 前已提到 As indicated in Table2 如表2所示As shown in figure 3 如图3所示As noted later 如后面所说明的If any 如果有的话，即使需要也If so 倘若如此If possible (necessary)如果可能（必要）If necessary 必要时，如果必要的话If required 如果需要的话When needed (necessary, feasible)必要时Where feasible 在实际可行的场合Where possible 在可能的情况下When in use 在使用时，当工作时4.It句型It appears that 看来.It can be seen that.可以看出.It
