【单选题】The majority of medium speed and high speed marine diesel engines for main or auxiliary drive operate on the _____ cycle.
【单选题】On Feb. 6, Xi’an – Zhenzhou High – Speed Railway,_________first high – speed railway in_______West China, was put into operation.
【判断题】病毒有抗青霉素的效应,是因为其不具有基因组。
【简答题】high-speed mixing gllinulation