根据字母提示，补全句子。

Mom: What are you 1. d _______?

Jack: I'm making a 2. b _______ chart for our 3. f _______. 4. W ______ is your birthday?

Mom: It's in 5. A _________.

Jack: My 6. u _______ birthday is in 7. A ________. too. When's my 8. f _______ birthday?

Mom: It's in 9. O _________. And your aunt's birthday is in 10. F _____.

Jack: Great! Here's the chart.

台风是一种破坏力很大的灾害性天气。某次台风把市民公园的一棵大树吹倒了，需要两个工人把它扶起，工人们想到了如图所示四种方案，每个人所需拉力最小的方案是（   ）