並前往https://books.google.com.tw/books?id=uY55VJZYWyAC&pg=PA121&lpg=PA121&dq=valve&source=bl&ots=J17D7agXe3&sig=ACfU3U1y0YFHtjcKQmfsyUP7YzHx43I94A&hl=zh-TW&sa=X&ved=2ahUKEwit4_yu9aH9AhVdg1YBHS95DFYQ6AF6BQjtAhAD