如图是受精卵经过分裂分化形成各种组织的示意图，据图回答33﹣35

根据对话情景及首字母提示, 填入所缺的词完成对话, 每空一词。

A: Ben, I have some questions about your country, Canada.

B: Okay. What do you want to know?

A: What are you s____ to do when you meet someone for the first time?

B: You're supposed to s____ hands.

A: How about time? For example, when a party is at eight o'clock, do you go at eight o'clock?

B: No, you can go about fifteen minutes late.

A: OK. Is it the same for business meetings?

B: Oh, no. For a business meeting, make sure you're o____ time.

A: Mmm…… , I heard that it's rude to make n____ when you eat. Is that true?

B: Yes, it is. You shouldn’t do it.

A: One more question, are you supposed to take a gift when you visit someone?

B: Yes, it's p____ to take some flowers.

A: Thanks. Now I’m ready.

一同学清晨刷牙时发现，当他用力匀速拖动牙刷时，牙刷毛发生如图所示弯曲．他对此进行分析，说法正确的是（  ）

FeS₂常用于在接触法制硫酸过程中产生CO₂，其化学方程式为：4FeS₂+11O₂ 2X+8SO₂，则X的化学式为（  ）