it

is

very

useful

to

your

english.

时间状语从句when,

whenever,

while,

as,

before,

after,

since,

till,

once,

as

soon

as,etc.

地点状语从句where,wherever

原因状语从句because,

since,

as,

for,

now

that,

etc.

目的状语从句in

order

that,

so

that,

that,

etc.

结果状语从句so…that,

so

that,

such…that,

that,

etc.

条件状语从句if,

unless,

as(so)long

as,

etc.

让步状语从句though,

although,

even

if,

even

though,

however,

whatever,

as,etc.

比较状语从句as…as,

so…as,

than,

etc.

方式状语从句as,

as

if,

as

though,

etc.