BackPoints on a ring
�@���i�������W�L���̉���QR�R�[�h���f�ځB�X�}�[�g�t�H���œǂݍ��ނ��ƂŁA�^�C���e�[�u�����ڂ������f�E�㉉�X�P�W���[���A�C���^�r���[�̑������L���ƘA�����������ȂǂɃA�N�Z�X�ł����B，详情可参考PDF资料
Main publication，这一点在PDF资料中也有详细论述
Three concerns are nicely separated and can be implemented independently:
Silver Plus sits between these two tiers, catering to serious amateurs or professionals on a budget.