它的发病与黄疸型肝炎的前驱期相似.The onset of this disease may resemble the prodromal period of icteric hepatitis.采用硝酸铁、硝酸锌、柠檬酸制备前驱体,在不同加热温度与速率下制备锌铁氧体.The citrate sol - gel synthesis method has been used to prepare zinc ferrite.以硫酸钛作为前驱...
伴随着隆隆的低沉噪声，螺旋桨开始旋转起来。With a low-pitched rumbling noise, the propeller began to rotate.头顶上，直升机在呼啸，巨大的螺旋桨叶片搅动着空气。Overhead, the chopper roared and the big blades churned the air.发动机使螺旋桨旋转起来。The engine turned a propeller....