中枢点向多个负荷供电时候，中枢点最低电压按照地区负荷时候计算，最高电压按照地区负荷时候计算， （填最大获最小）

A. 区域水、火电厂的母线
B. 枢纽变电所、有大量地方负荷的二次母线
C. 有大量地方负荷的二次母线
D. 任何节点

A. It helps to gain a general understanding of the listening materials.
B. It helps to improve your language fluency and build up your vocabulary.
C. It is the detailed and focused listening.
D. It can be extended for a long time over a variety of topics.

A. Materials appropriate to your level.
B. Authentic listening materials.
C. Materials on a topic that you are already familiar with.
D. Materials on a topic that you're interested in.
E. Difficult materials that are very challenging to you.