we should not leave the blue flame of a bunsen burner unattended because
a.the flame is noisy
b.someone may not see the flame and burn himeself/herself
c.it produces soot and a bad smell
d.striking back may happen due to the opened air hole
123321
2007-10-26 4:50 am
回答 (4)
2007-10-26 4:57 am
✔ 最佳答案
應該是d！
2007-10-27 7:30 am
有藍火是因為燃燒良好, 因此c是不正確
而d只會在點火時發生
因此答案是b,
a記得不是, 但不肯定
而d只會在點火時發生
因此答案是b,
a記得不是, 但不肯定
2007-10-27 2:52 am
The most important point is b !
Because somebody has touch it, it will hurt the him.
So I think the answer is b !
2007-10-26 18:53:17 補充：
Sorry !!!!!!!!!!!!!!!!I think type a extra word.' The ' !!!!!!!!!!!!!!!當它沒存在 。
Because somebody has touch it, it will hurt the him.
So I think the answer is b !
2007-10-26 18:53:17 補充：
Sorry !!!!!!!!!!!!!!!!I think type a extra word.' The ' !!!!!!!!!!!!!!!當它沒存在 。
參考: Me
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