用A、B两刻度尺测同一木块的长度，就分度值而言，A尺精确些；就使用方法而言，____ 尺不正确，从用法正确的尺上读出此木块的长度为____ cm．

根据对话内容及方框内所给句子补全对话，有一项是多余选项。

A: How nice to see you back, Li Lei!

B: Hi, Judy! I just came back yesterday.

A:____

B: Wonderful! I've been to many places of interest and I enjoyed myself in Disneyland.

A:____

B: Not really. Sometimes I got into trouble. They spoke too quickly and I couldn't have long conversations with the people there.____

A: Yes, I agree. I know English is very important, but I often feel sleepy in English classes.____

B: I'm afraid, too. And it's very difficult for me to remember new words.

A: Me, too. I don't know what to do____

B: Don't let these difficulties discourage(使气馁) you. Remember: where there is a will, there is a way.

A: Sure, I won't. I'll try my best.

B: So will I.

A. How was your trip?

B. At times I feel like giving up.

C. What did you buy in the USA?

D. I'm really afraid of the final exam.

E. I think I should work harder in English.

F. Could you make yourself understood in the USA?

某段电路的电阻为R，电路两端的电压为U，通过的电流为I，通电时间为t。则在时间t内电流通过这段电路所做的功（   ）

今年上半年，全国法院受理的劳动争议案件呈井喷态势。2009年7月13日，最高人民法院相关负责人接受《财经》记者采访时透露，今年上半年，全国法院受理劳动争议案件近17万件，同比增长30%。实现和维护劳动者权益是社会主义制度的本质要求。劳动者获得权利、维护权益的基础是                                                                                                      (　　)

在细胞分裂过程中，____的变化最为明显，由于它的变化，使得经过细胞分裂形成的两个新的体细胞中的____与原来细胞中的完全相同。