从属连词有：so that, in order that或that等，从句中常含有情态动词。
they carved the words on the stone so that/in order that the future generation should/might remember what they had done.
他们把字雕刻在石头,以便/为了未来一代应该/可能还记得他们所做的事情。
we climbed high (so) that we might get a better view.
我们爬的高才能看见更好的风景。
the teacher raised his voice in order that the students in the back could hear more clearly.
老师高喊嗓子，以便后面的同学听清。
*联想省略后的不定式in order to do/so as to do（逻辑主语或相同）或in order for sb to do（逻辑主语不同时）。
all the key words in the article are printed in bold type so as to attract readers’ attention.
刊登在报刊上的文章都把关键字放大,以吸引读者的注意力。
考题
____ measure matter we must have units of weight, volume and length. (cet-4)
a.in order
b.in order to*
c.so as
d.so as to
*so as to不可用于句首。因为so本意为“如此”，只有先说了些什么，才谈得上“如此”“怎样”。
lest, for fear(that), in case: 以免、以防，深怕……
take an umbrella with you lest it should rain.
带上伞以防下雨。
people evacuated the building for fear that the wall should collapse.
人们撤离大楼担心墙壁倒塌。
she cleans the window with great care lest she might break the window.
她清洗窗户小心翼翼以免她可能打破窗户。
we had a meeting and talked the matter over face to face, for fear that there should be any misunderstanding.
我们有一个会议,谈论此事在面对面,担心应该有任何误解。