In the first case it means light as a feather, weight wise and in the second case we're talking about light as opposed to dark. So that's the fallacy of equivocation.
第一句中是指羽毛很轻，在重量方面的，第二句是，与黑相对的亮，这就是模糊谬论。
2
If this is not the case the black weight will look optically too small when it's combined with the light weight in a line of text.
否则，当粗黑体和细线体在同一行中连排时，粗黑体看上去就要比细线体要小得多。
3
As is the case with those other mechanisms, WS-Inspection documents are very light-weight, easy to construct, and easy to maintain.