1) Sth. is like/as...as/similar to/the same as/compared to/as if (though) ...(明喻)
e.g. In the eyes of book worms, books are compared to/like a magic blanket that carries them anywhere as they like.
2) Sth. is/refers to/is nothing but...(暗喻)
e.g. For/To a seeker after the treasure of knowledge, learning is rowing across an unbounded ocean, in which hardship is seen as his boat.
3) Sth. is thought of/defined/valued/cherished/seen/esteemed as...
e.g. A true friend is valued not only as your shadow that comforts your body but also as your mirror that helps you find any dirt on your face.
4) A does sth. just as B does sth. else.
e.g. Educative experiences of life can tell us how to get rid of failure, just as weather beaten sailors know how to steer clear of rocks.
5) Sth. means/signifies/stands for/is a symbol(matter/sign/token)of...
e.g. Love is not a matter of seeking self-satisfaction; it is first a matter of giving and then discovering, as an unexpected gift, the deepest satisfaction one can know.
1) Only in this way/Only when.../Only through...will/can we...
或：It is only if/when...that we will...
e.g. It is only if all sides of society take their roles fully that we will achieve the society we want.
2) As/So long as...we will be able to.../the problem is bound to...
e.g. As long as we persist in spreading scientific knowledge among the masses, all the superstitions are bound to go out of our life.