发现视觉残留原理的科学家是（） 科尔。 勃莱克顿。 雷诺。 约瑟夫.普拉托。
质量分布调查表与直方图的频数分布表有何不同？
石油的组份是什么？
注塑模的冷却装置，一般装在（）。 模具型腔及型芯周围。 模具型腔及型芯内。 分型面处。 模具周围。
Your vessel was damaged and initially assumed a significant list and trim; however，further increase has been slow. Based on this data，what should you expect?（） The slowing is only temporary and the vessel will probably suddenly capsize or plunge from loss of stability due to change in the waterplane area。 The vessel can probably be saved if further flooding can be stopped。 The vessel will continue to slowly list and/or trim due to the free surface effect and free communication effect。 The vessel will suddenly flop to the same or greater angle of list on the other side and may capsize。
以下哪些属于劳动合同的必备条款（）
