在负载电路中串联电阻可起到的作用有哪些（） 分压。 分流。 调节电流。 限制电流。 增大负载功率。 调节频率。
In the variable delivery pump, moving the spindle more from the central point will cause （） fluid to be pumped and consequently （）pressure is generated to drive the rams. more；more。 more；less。 less；more。 less；le。
A towing vessel should be on the crest of a wave at the same time as its tow and in the trough at the same time. The term used to describe this is（）. tow strain。 catenary length。 being in step。 Williamson's Tow。
A towboat has the same draft as the barges it is pushing ahead. If the distance from the stern of the towboat to the head of the tow is 260m，where is the approximate location of the pivot point of the unit?（） At the head of the tow。 75m from the head of the tow。 120m from the head of the tow。 180m from the head of the tow。
固体燃料的燃速率只取决于其本身的结构，与燃料与空气接触的面无关。
下面左图表示的是pH对植物和人的淀粉酶活性的影响；右图表示的是3种脱氢酶（A、B、C）的活性受温度影响的情况。下列叙述正确的是（）
