已知数列1，a₁，a₂，4成等差数列，1，b₁，b₂，b₃，4成等比数列，则 $\frac{a_2-a_1}{b_2}$ 的值是（   ）

甲和乙两个分子，设甲固定不动，乙从无穷远处（此时分子间的分子力可忽略，取无穷远时它们的分子势能为0）逐渐向甲靠近直到不能再靠近的过程中（  ）

如图为突触结构模式图，下列说法不正确的是（　　）

阅读下列短文，从每小题所给的A、B、C、D四个选项中选出最佳选项。

    Look at the girl. Her name is Lucy. And this lovely girl is her twin sister Lily.1parents are both （两者都）teachers. They work hard.

    Lucy and Lily2at No.4 Middle School. They go to school3Monday to Friday. They have no classes on Saturdays and Sundays. They have breakfast at 6:30. They go to school at 7:00. Classes

    4at eight. They have four5in the morning and three in the afternoon. They have6at 12: 15. At 3:50,they have sports.

    Lucy and Lily study Chinese, math, English, geography, physics, history and other lessons. Lucy's favorite7is music,8it's relaxing. Lily likes science best. She thinks it's difficult 9interesting.

    Their parents like reading. They often read books at home. Their parents are strict(严厉地)with  them, but sometimes they are very kind and friendly to their children. Lucy and Lily love their10 very much.

根据短文内容。选择适当的短语完成句子。    A man goes to a fast food restaurant for lunch. "Hi!" a waiter says. "Can I help you?"
    "I'd like a hamburger。French flies and a medium pizza, "says the man.
    "Anything else?'' the waiter asks.
    "No, "the man answers. "That's all. ''
    "Is that for here or taking away?" the waiter asks.
    "Taking away, "says the man.
    The man pays for his lunch. The waiter puts the man's lunch in a bag. 'The man takes the bag away.
    "Thank you!" the waiter says. "Have a nice day."
    The man walks to a park. He sits down and opens the bag. To his surprise(使他吃惊的是), there are no hamburgers in the bag. There are no French fries. There is no pizza. There is money(钱)in the bag a lot of money. The man counts the money--2, 000 dollars!
    Why is the money in the bag? The man doesn't know. Do you know? Can you guess?

A. to a park      B. a lot of money      C. the man's lunch in a bag D. "I'd like a hamburger, French fries and a medium pizza.'' E. to a fast food restaurant for lunch