太阳每天都是新的，人每天都在变化。我们要使自己更完美，就要正确认识自己。要正确认识自己，就要（   ）
①全面地看待自己                                                   ②用发展的眼光看待自己
③只需看到自己的优点，不必知道自己的缺点   ④提高自己的内在素质，不必太在意自己的外在形象 

根据短文内容，选择正确答案。

    Tom walked into a shop. It had a sign outside: “Second-hand (旧的）clothes bought and sold.” He was carrying an old pair of trousers and asked the owner of the shop, “How much will you give me for these?” The man looked at them and then said,“Two dollars. ”

  “What?!” said Tom. “I thought they were worth at least five dollars.”

  “No,” said the man “They aren't worth a cent more than two dollars.”

  “Well,” said Toni, taking two dollars out of his pocket. “Here's your money. These trousers were hanging outside your shop. The list price (标价）of them was six dollars and a half. But I thought that was too much money, so I wanted to find out how much they were really worth.”

    Then he walked out of the shop with the pair of trousers and disappeared before the shop owner could think of anything to say.

在矩形ABCD中，AB=1，BG、DH分别平分∠ABC、∠ADC，交AD、BC于点G、H．要使四边形BHDG为菱形，则AD的长为____ ．

“朝为田舍郎，暮登天子堂”是古代中国许多知识分子的追求，隋唐以后他们实现这一理想的主要途径是（    ）