Electronic contracts are an exciting new option for those looking for a better way to do business. Transmitted instantly, without the expenses of printing or shipping, electronic contracts can allow you to do business with clients hundreds or even thousands of miles away, at a fraction of the cosplayt. The key technological innovation enabling this new business paradigm? Electronic signatures a legally binding, secure version of the handwritten signatures you use to sign paper documents today. The key technological innovation enabling this new business paradigm?
enabling作谓语，这里的问号，是反问什么？
Electronic signatures a legally binding, secure version of the handwritten signatures you use to sign paper documents today. Electronic signatures a legally binding是独立主格结构吗？若是，是名词+副词短语的形式吗？
The key technological innovation enabling this new business paradigm? Electronic signatures a legally binding, secure version of the handwritten signatures you use to sign paper documents today.
这个问句和后面的陈述句都是省略句，都只不过一个名词词组。
The key technological innovation enabling this new business paradigm? 这是一个设问句，作者自问自答。省略了系词和作表语的what.
the key technological innovation enabling this new business paradigm?
enabling并非谓语（非限定动词如何能作谓语？），而是innovation的定语。
Electronic signatures a legally binding, secure version of the handwritten signatures you use to sign paper documents today.
这个句子没谓语动词，是设问句的答案，省略了主语和系词be.
electronic signatures, a legally binding, secure version of the handwritten signatures you use to sign paper documents today.
其中，a legally binding, secure version of the handwritten signatures you use to sign paper documents today.是一个以version为中心词的名词词组，作electronic signatures 的同位语。
