根据句意,用括号中所给音标或词的正确形式填空,每空填一词.

1. Mrs. White works in an office. She often           ['u:zΙz] a suit to wear.

2. I'm new here, but all my classmates are           (friend) and helpful to me.

3. —Who is the          (one) to come to school?  —Oh, it's Mary.

4. The boy likes eating chocolate and sweet food, so his          (tooth) are getting worse.

5. This is the           (player) sweater. Please give it to him.

简述因果分析的主要形式。