1.…,which leads to…
例句：I couldn’t sleep with the noise of the traffic.
3.The reason why…is that…
The reason why后面接结果，is that后面加原因，都是写完整的句子。
4.This is because…
5.The main/primary reason is that….
6.That is why….
例句：That is why this year is likely to be just the beginning of many discussions like the one at the Munich security conference.
7.It is only because…that…
例句：It is only because we have become used to these extraordinarily fragile structuresthat this demand seems so outrageous.
例句：Unions often rely on volunteers to administrate,thereby keeping costs at a minimum.
例句：This is due to ignorant motorists who fail to stop and thereby put the lives of her and the children at risk.
例句：A second object was described to be identical to the one seen by the second mission,leading to the same conclusion as to its risk.
1.be a contributing factor
例句：Human error may have been a contributing factor.
2.be a factor contributing to
3.be a contributory cause of
例句：Smoking may be a contributory cause of the disease.
4.be contributing to
be a major contributor to
…be attributed to
…be attributable to
例句1：Supermarkets are the main contributors to this mountain of food.
例句2：Juvenile delinquency can be attributed to parental permissiveness.
例句3：The health problems are attributable to a poor diet and lack of exercise.
1.…,not least because…
2.…,in large part because
例句：Despite well-intentioned policies and laws,the situation on the ground is often quite different,in large part because of the difficulty of enforcement,both within and across borders.
3.…,if for no other(better)reason than
例句：It is essential,if for no other reason than for a unity in teaching,that each member of the school community adopts a common outlook on life.
4.…,because at least…
例句：Monotony is a big problem for the moralist because at least half of human's bad habits result from his fear of it.
5.…,if only because
例句：We are confident if only because we are making progress.
例句：So scarce is the food that many people suffer from starvation.
例句：Such is the moment that all greats traverse.
例句：Another excellent way to eliminate error messages is to make the application smartenough that it no longer needs to make unnecessary demands.