根据句意和汉语注释，在答题卡标有题号的横线上，写出单词的正确形式。

1.I’m so helpful that it's my ______ (please) to help give a seat to somebody in need.

2.The final-exam is coming. The students are ______ (active) revising for tests.

3.Because many factories pour waste water into the river, we must take action to change the______ (pollute) environment.

4.It’s known to all that this trail is the ______ (far) one we have ever walked.

Jane Scott is fourteen and the year before last she began to study in a middle school. She likes dancing and singing and spends a lot of time on them. But she hates math and does not work hard at it. She thinks it difficult to learn. She falls behind her classmates and once failed the math exam. She decides to drop it. Her father is angry with her when he knows about it.
It was Sunday. Mr Scott gave a call to his sister, who teaches math in another school. He hoped she would come and tell his daughter how to learn math. The woman came quickly and said. “You’re a clever girl, Jane. I’m sure you’ll soon do well in math if you work hard at it.”
“I’m afraid I can’t, Aunt,” said Jane, “Girls can’t be good at math.”
“I don’t think so,” said the woman. “I was good at it when was a girl. You must do more exercises and practice a math problem again and again until you master it. Remember: Practice makes perfect. Well, it’s a math problem. Think about it and practice it again, and you’ll work it out.”
“OK,” said the girl, “Let me try.”
About an hour later, Jane took the exercise book to her aunt and said, “I’ve done the problem ten times.”
“Well done!” her aunt said happily, “What result did you get?”
“Ten answers.”
【小题1】Jane has difficulty in learning ______.

根据句意和汉语注释，在答题卡标有题号的横线上，写出单词的正确形式。
【小题1】I’m so helpful that it's my ______ (please) to help give a seat to somebody in need.
【小题2】The final-exam is coming. The students are ______ (active) revising for tests.
【小题3】Because many factories pour waste water into the river, we must take action to change the______ (pollute) environment.
【小题4】It’s known to all that this trail is the ______ (far) one we have ever walked.