古人说：“合抱之木，生于毫木；九层之台，起于垒土；千里之行，始于足下。”这告诉我们：培养和锻炼坚强意志要（    ）

下列关于气温变化的叙述，正确的是 （    ）

使用显微镜时，进行对光，依次调节哪些结构（　　）

请认真阅读下面短文，并根据各题所给首字母的提示，写出一个合适的英语单词完整、正确的形式，使短文通顺。
   Kitty was a student in a small town. It was going to be her mother’s birthday. She wanted to buy her a present that would be nice and useful but not e____ .
   She went s____  after a quick and simple lunch. After she looked for about forty minutes, she found a shop that was selling cheap umbrellas, and she d____   to take a black one. She thought, “Mom can carry it when she is wearing clothes of any c____ .” So she bought a lovely black umbrella and took it to school with her until her classes finished.
   On her way home on the train she felt h____ , so she went to the buffet car (餐车). She left the umbrella on her seat and left. But when she remembered it and r____  for it, it was gone. Kitty began to cry. The other passengers felt very sorry for her and asked what was the matter. She told them the black umbrella she bought for her mother was gone, and she had to get off at the next station. After the three passengers h____  this, they asked her for her mother’s  a____  so that they could send the umbrella to her if someone took it by mistake (弄错) and brought it b____ .
   And now a week passed. Kitty got a letter from her mother. It said, “Thank you very much for your lovely g____ , but why do you send me three black umbrellas?”