123321

Question

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

Answer 1

Favorite Answer

應該是d！

Answer 2

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

Answer 3

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 。

Source(s): Me

Answer 4

It should be B and D......

Source(s): ME