1. There are several reasons for…, but in general, they come down to three major ones.有幾個(gè)原因……，但一般，他們可以歸結(jié)為三個(gè)主要的。

　　2. There are many factors that may account for…, but the following are the most typical ones.有許多因素可能占...，但以下是最典型的。

　　3. Many ways can contribute to solving this problem, but the following ones may be most effective.有很多方法可以解決這個(gè)問題，但下面的可能是最有效的。

　　4. Generally, the advantages can be listed as follows.一般來說，這些優(yōu)勢可以列舉如下。

　　5. The reasons are as follows.