要闭合多边形套索创建的选区，可以执行下列操作中的哪些方法？（） ["按Esc键","按Enter键","单击工具箱中的其他工具","按Ctrl键单击"]
The connecting rob is fitted between the crosshead and the crankshaftIt transmits the firing force, and together with the crankshaft convert the （） motion to a （） motion. ["rotary；reciprocating","up and down；fore and aft","fore and aft；up and down","up and down；rotary"]
电感线圈的电工符号如图所示。
营销人员在（）过程中，其目的不仅是在推销商品，同时也是在建立关系，树立形象。 ["A.沟通","B.市场调查","C.推销交际","D.推荐产品"]
LED现有哪些知识产权？
为什么说诚实是做人的根本？
