Occasionally, a bubble is not removed during refining, a sand grain refuses to melt, a tremor in the tin puts ripples into the glass ribbon.

"有时候，在提炼的过程中会出现这些情况：一个气泡没有被移除，一个砂粒没有熔化，（熔融的）锡的一次颤动把波纹带进了玻璃带中。