What is the purpose of the intake/exhaust valves in a diesel engine? （） ["They regulate the combustion cycle","They supply cooling water","They synchronize the ignition spark","They supply and regulate the lubricant flow"]
下图是一个位于我国湖北省黄冈的著名遗址，请问哪位诗人在这里写出什么著名诗篇。
测算株高方法，用手抓住一穴向上捋，由地面量至（）为该穴平均株高。
D200网络型系统模块有哪些功能，其优点是什么？
What is the operating principal of a flash type evaporator?（） ["Sea water is heated to boiling temperature under a vacuum","Sea water is passed over heated plates in a thin film","Heated sea water is injected into a vacuum chamber","Sea water is forced through a heated eductor"]
叶龄标记点的叶龄必须选准，叶龄全部点在（）上，起始叶要从第（）叶开始，并且跟踪到（）期。
