如图装置可以用于实验室过氧化氢溶液制取氧气：此装置中长颈漏斗的作用是____ ，如果用注射器代替长颈漏斗好处是____

Subject: Can you help?            

From: Rose

Dear Knowledgeable,

    I have a good friend, Ann. She is very clever and can speak English really well. A very important English speech contest for our whole city will be held next month. Our classmates all think Ann is the best person to represent the class in the school contest and make sure she will win. But the problem is that she's very shy and that she's terrified of speaking in front of other people.

    She can't tell others about it, because she doesn't want to let her friends down. I can't think of any good advice to give her, but you always come up with good solutions to people's problems. Can you give us some good advice？Do you think we can tell the truth to the rest of the students?

Yours,

Rose

如图所示是小明“探究不同物质吸热升温现象”的实验装置。用同一套装置，先后加热并不断质量相等的煤油和水。