皮皮学，免费搜题
登录
搜题
【判断题】
三相四线制供电系统中,电源线电压与相电压的相位关系为线电压滞后于对应相电压30度。A.
正确
B.
错误
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】What is the main idea of this whole reading?
A.
People of polychronic cultures need to learn how to keep to deadlines and become more organized.
B.
Understanding the two cultural time systems, monochronic and polychronic, may be helpful in getting along with others.
C.
Everyone in the world should adopt the same approach to time since it is annoying when others are different.
【简答题】如图，AB ⊥BD 于点B ，ED ⊥BD 于点D ，AE 交BD 于点C ，且BC=DC. 求证：AB=ED.
【简答题】如图，AB⊥BD于点B，ED⊥BD于点D，AE交BD于点C，且BC=DC．求证：AB=ED．
【简答题】如图，在△ABC中，∠C=90°，∠ABC的平分线交AC于点E，ED⊥AB于D，如果AC=6，则AE+ED=______．
【简答题】如图，已知：CF⊥AB于F，ED⊥AB于D，∠1=∠2， 求证：FG∥BC
【简答题】已知：如图，△ABC中，∠C=90°，∠A=30°，ED垂直平分AB交AB于D，交AC于E．求证：ED=EC．