Zd
n. 天頂距（zenith distance）；零色散（Zero Dispersion）
??? 情景例句
I'll chop the onions.
我要去切洋蔥。
I can't seem to get to sleep.
我好象睡不著。
In this way self-confidence grows, first from mastering a subject, then from being able to take about it.
這樣，你自信心不斷增強(qiáng)，先是因?yàn)檎莆找婚T學(xué)問，接下來是因?yàn)槟軌蚓痛税l(fā)表見解。