【简答题】阅读理解 Let us suppose it is now AD 2060. Let's believe it is fifty-three years from now. Of course, things have changed and life is very different. Travels to the moon are being made every day. It is a...
【单选题】---Why ____ go to the supermarket with us ? ---Sorry , he is doing his homework now.
【简答题】阅读理解。 Life in 2060 Let us suppose it is now about A.D. 2060. Let's imagine it is about fifty years from now. Of course, things have changed and life is very different. Voyages to the moon are being ma...
【单选题】Let's do ________ homework now. [ ]
【单选题】对称星形负载 R 接于 对称 三相三线制电源上,如图 所示。若电源线电压为 380 V ,当开关 S 打开后电压表的测量值为 ( ) 。 (a) 380 V (b) 220 V (c) 190 V ( d ) 110V
【简答题】一星形联接的三相负载电路,三相电源电压对称。设 电源每相U、V、W线电压可用 , 每相分别滞后120度。 1 画出该电源向量图 2 如果采用 三相四线制输出,并接于三相对称负载灯泡:R U =R V =R W =22 Ω,求每相的线电流和向电流?此时中线电流等于多少? 3 如果将其中R W 换为11Ω,仍接于三相四线制,各相电流如何变化?那个灯泡最亮?此时中线电流等于多少? 4 如果上述不对称电路...
【简答题】完成测回法 水平角观测记录表格计算,并说明最终水平角的大小。 测回法水平角观测记录.docx
【多选题】水平角观测方法有测回法和方向观测法,水平角观测的测回法限差有半测回较差和测回间较差,方向观测法的限差有______。
【简答题】Let us go now, _____?