ug/ml：microgramme per mililiter

第一个差得也忒远点啦——不是乙醛，是…等（其他）人 的意思

1‰：one in a thousand

et al. abbr.
1. =et alii 【拉】以及其它人
2. =et alibi 【拉】以及其它地方

听即时发音 : http://hk.dictionary.yahoo.com/search.html?s=et+al

98∶2 ninety eight to two

No. 2377/90 : Number two three seven seven slash (or stroke) nine zero (or Number two three double seven slash nine zero, Number twenty three hundred and seventy seven slash ninety, Number two thousand three hundred and seventy seven slash ninety……)

(Remark : A slash or stroke, /, is a punctuation mark. It is also called an oblique dash, diagonal, separatrix, virgule, scratch comma, forwardslash, or slant. It appears similar to a solidus or shilling mark, which is a separate character. (Note: not to be confused with the word "virgule" in French, which means "comma"). It is sometimes incorrectly called a backslash.)

98∶2 ninety eight is to two或the ratio of ninety eight to two

→ arrow
↑ 待补充
♂ 待补充
＃ number…号
＼ virgule 或back slash (A＼B 也可以是difference of A and B或A minus B)
* asterisk

自以为英语还行，一看到这些符号，知道自己还需努力。

">" : greater than
"<" : less than
“∝” : in direct proportion to
10^-7 （是10的-7次方） ten to the power minus seven

22.50±0.50 ℃ : twenty two point five zero plus or minus point five zero degrees Celsius