解释下列加线的词语

族兄中涵知旌德县时。____径搏老翁____老翁手一短柄斧____

除去下列物质中混有的少量杂质，所用除杂试剂及操作方法均正确的是（　　）

地沟油中含有杂质及有毒物质，很多人猜想它的密度应该比正常食用油的密度大，为了验证这种猜想，小华同学找到质量为0.46kg的地沟油，测出其体积为0.5L，该地沟油的密度为多少？请问能否用密度这一指标来鉴别地沟油？（已知正常食用油的密度约为0.91×10³kg/m³～0.93×10³kg/m³）

下列各句中，没有语病的一句是                                      (　　)

AMary: Hello, Gina. Do you want to have evening classes? On Monday evenings, there is a guitar (吉他) class.

Gina: I'm busy on Mondays. What about Tuesdays?

Mary: There's a class to teach you how to make bread. The teacher is Mr. Smith.

Gina: The class is useful. And Mr. Smith's bread is great. And Wednesdays?

Mary: That class is about clothes. You can learn how to make clothes.

Gina: It's fun. What class do you want to take?

Mary: Well, on Thursdays, there's one interesting class. I can learn how to make model planes.

Gina Oh, that's great. But I'm busy those days.

Mary: There is another (另一) interesting class on Friday evenings. You can learn about the stars.

Gina: It's boring. Is there a class on Saturdays?

Mary: Yes, you can learn how to take pictures.

Gina: Great! I like this class. I'll take it.

根据材料内容选择最佳答案。