umthamo wokuthengisa kumazwe angaphandle uqhubekile ukonyuka, kwaye isebe lorhwebo lwangaphandle liqhubekile nokukhula. Izixhobo ze-ultrasonic ze-Wanli zifumene iimpendulo ezintle kubathengi basekhaya nabangaphandle, kwaye imarike yamazwe ngamazwe yavula ngokukhawuleza.
