9)层进
first， in the first place， to begin with， second， next， in addition to， besides， moreover， furthermore， third， finally
10)强调
indeed， in fact， certainly， particularly， above all， most importantly， worst of all
11)目的
in order to， in an effort to， so as to， in order that， for fear that， in case， least
12)先后
shortly after， earlier， later， afterwards， after， before， once， meanwhile， since， until， when， while， the moment， as soon as
13)指示
this， that， these， this accounts for， this helps explain， that's why
