开口沈箱 Open caisson

开口沈箱码头 open caisson wharf

沈荣开 Rong-Kai Shen

开口沈箱基础 open caisson foundation

沈默乒乓开关 silence toggle

沈阳高压开关厂 Shenyang High Voltage Switchgear Factory

沈阳低压开关厂改造 restoration of shenyang low voltage switch factory