大全 61    介词短语的位置

After crude oil, natural gas is the United States second biggest fuel source and supplied almost exclusively from reserves in North America.

(A) After crude oil, natural gas is the United States second biggest fuel source and supplied almost exclusively from reserves in North America.

(B) Natural gas, after crude oil the United States second biggest fuel source, supplied almost exclusively from reserves in North America.

(C) Being supplied almost exclusively from reserves in North America, natural gas, the United States second biggest fuel source after crude oil.

(D) Natural gas, the United States’ second biggest fuel source after crude oil, is supplied almost exclusively from reserves in North America.（D）

(E) Natural gas is supplied almost exclusively from reserves in North America, being the United States’ second biggest fuel source after crude oil.

A E  的介词短语AFTER 位置都不好，大家能不能说说一般介词短语放在句首（A），句尾（E）  各自表示什么修饰含义呢