原句中的定语从句、宾语从句对句意表达的作用不大，可以略过不读。
通过对复杂修饰成分的加工处理，这个句子变得十分简单：One of the principal reasons is that they lack access to the sizable orders and subcontracts.
考研阅读的复杂修饰成分往往放在一个比较复杂的句子框架中，例如下面这句话：Although the samurais had been reduced to idleness by years of peace， encouraged to engage in scholarship and martial exercises or to perform administrative tasks that took little time， it is not surprising that their tastes and habits grew expensive.
