Delta metal
[機] 德他合金
?? 詞語組成解析
delta
['delt?]
n. 希臘語字母表第四字母δ;（河流的）三角洲;[數]變量增量;
metal
['m?tl]
n. 金屬;金屬元素;成色;金色;
vt. 以金屬覆蓋;
??? 情景例句
What are you working on?
你在干什么？
She looks blue.
她滿面憂傷。
and by measuring the time interval between the taps and the receipt of the echoes, the depth of the sea at that point can be calculated.
測出回聲間隔的時間，便可算出該處海洋的深度。