表原因的高级句型有：the reasong why......is that ；it is because......；that's why i......，Many factors weigh heavily for…（很多因素对…影响很大。）；Another contributing factor/ cause is …（另一个有影响的因素是…）；等，It is not simple to give the reason for this complicated phenomenon（指出复杂现象的发生原因不是那么简单）等等。
除此之外，人们还会用一些表原因的连词：as, since ,for, because，for this reason，due to，thanks to，owing to等连词放在句中，表示原因。