本题

What you said is irrelevant to the subject.

你说的与本题无关。

Because the main subject involves the strong corrosive acid, has used the glass lamella lining especially.

由于本题涉及强腐蚀性的酸，特采用了玻璃鳞片衬里。

I would like to know if I could ask for a sick leave of absence from classes for two days.

从本题所给的信息可以判断出，这里要求完成的是一封请假信。

Leaver was stricken with cancer 50 years ago.

解析：21。意思是：短文倒数第二段最后一句说" Leaver 50年前战胜了癌症，这是第一次，也是唯一的一次"，可见本题是正确的。

A left-luggage office is a place where bags___ be left for a short time, especially at a railway station.

答案为 B。本题考查对于情态动词在特定语境中运用的掌握情况。

What is the main subject of the conversation?

本题考查的是会话的主题。

In 1858 he sent me a memoir on this subject.

他于1858年，曾寄给我关于本题的一篇论文。

Nonimmigrant visas for journalists are among the most widely known.

本题为细节题，侧重点是综合信息能力。

One hundred and eleven cases of acute cerebral infarction were divided into 8 groups based on treatment methods and the sequence of attack.

本题选择 111例急性脑梗塞患者，根据治疗方法和发病时间顺序将其分为 8组。

W: Not now, it ' s out of season and they are all very cheap.

本题考核获取重要的事实信息的能力。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。