The elements linked by a coordinating conjunction are necessarily parallel in meaning. (Here, of course, “parallel” does not mean “the same”: the two clauses in “give me liberty or give me death” have quite different meanings, but the meanings are parallel.)[并列联次连接的句子成分大体上在意思上是平行的，但不一定相同]

Since the function and meaning of coordinate elements are parallel, it follows that, for logic and clarity, they should be expressed in parallel form. There are degrees of parallelism, and perfect symmetry is both rarely achieved and rarely necessary. But at a minimum, parallel form means that the words or groups of words in a pair must belong to the same grammatical category. [平行格式意味着成对词语或者成对词组的语法分类必须相同]

原句：Also to be coordinated [between Hong Kong and Guangdong] are water supply, security, and how to move people and trucks across the border more efficiently. [名词+ 名词 +不定式短语]

修改：Also to be coordinated are water supply, security, and efficient movement of people and trucks across the border. [三个名词]

原句：Timber is needed for construction and to withstand flood. [介词短语 + 不定式短语]