下列营养物质中，能为人体生命活动提供能量的（    ）

①糖类 ②脂肪 ③蛋白质 ④水 ⑤无机盐．

某双链DNA分子有100个碱基对，其中有腺嘌呤35个，下列叙述正确的是（    ）

某农科所做了两个小麦品系的杂交实验：70cm株高（以下表现型省略“株高”）和50cm杂交，F₁全为60cm。F₁自交得F₂，F₂中70cm：65cm：60cm：55cm：50cm约为1:4:6:4:1。（题中小麦的基因型，若涉及1对等位基因，用A、a表示，若涉及2对等位基因，用A、a、B、b表示。）

      Computers can help many workers. They can also help thieves.
      There was one thief who worked in a bank of the United States. He paid for everything he needed by check (支票). Then he told the computer not to take any money from his account for the checks he wrote. The bank's computer did what he said. And it did not take any money from his bank account. One day the computer broke down. People had to do the computer's work. They soon found out what was happening.
      Another thief, who worked for a bank saw people filling in deposit forms (存款单). Many of these people did not know their account numbers, so they wrote only their names on the forms. They left empty places for their account numbers. The thief wrote his own account number in this place. When the computer read these forms it looked only at the account numbers. It did not look at the customers' names. It paid the money on these deposit forms into the thief's account .                           
       Then there was the bank worker who told the bank computer to take ten cents off every customer's account each month and put it into his own account. For a long time the bank's customers did not notice that they were losing ten cents every month. But then someone did notice and told the bank. That was the end of that little game!

参加飞行比赛的动物有哪些共同特征？它们身体的哪一部分比较发达？