The VRLA battery was the basicpowersource for electric bicycle applications.
阀控式铅蓄电池仍是电动自行车的主要电源。
2
School constitution that is concretion and complementary of laws is the basicsource of principal's power.
学校章程构成校长权力的基本来源，其对校长权力的规定，是对学校校长法定权力的具体化和补充。
3
The article describes the basic requirements for the powersource of the metro power supply system, analyzes briefly the features of various power supply modes and their selection.