A drop in compression pressure in one cylinder of a diesel engine can be caused by（） ["a leaking fuel injection nozzle","a clogged air filter","early fuel injection","burned valve"]
A grapnel is a（）. ["device for securing a chain topping lift","hook to prevent the anchor cable from slipping","device used to drag for a submerged cable or line","type of clam bucket used for discharging bulk cargo"]
何为A+、A、B、C、D类供电区域供电可靠性规划目标？
如何获得多倍体植物？（） ["用植物进行自花传粉，于是获得纯合子系；纯合子系自交，于是表现杂种优势","先选择人们所需要的个体，将其性器官暴露在射线之下，由于基因和染色体发生变化，新的遗传特性就出现了","为提高生产力，从许多系中进行选择，再进行杂交即可","用秋水仙素处理，正在分裂的细胞的纺锤丝瓦解，于是成对的染色体不能在有丝分裂的细胞中向两极分开"]
A deck beam does NOT（）. ["act as a beam to support vertical deck loads","lessen the longitudinal stiffness of the vessel","act as a tie to keep the sides of the ship in place","act as a web to prevent plate wrinkling due to twisting action on the vessel"]
在什么情况下，需要为DHCP客户机设置IP地址的保留？
