3. 探索营里，同学们正在记录生活中力与运动的因果关系。请你选择合适的词语，完成记录卡。
heavy light small big easy difficult push pull further near

Cause: I use a pulley.
Effect: I can lift the ① bucket with a ② force.
Cause: I use a ramp.
Effect: It is ③ to ④ a big stone to go from the higher place to the lower place.
Cause: I use a slingshot.
Effect: The stone can go ⑤.

① heavy ② small ③ easy ④ push ⑤ faster / further

4. 同学们正在进行科学判断大闯关。请你判断正（T）误（F），并圈一圈。
① It’s more difficult to carry a full shopping bag than an empty one. ( T / F )
② It is easier to slide on a wet floor than on a dry one. ( T / F )
③ Running needs a smaller force than walking. ( T / F )
④ A small push makes the door open slowly, and a big push makes it open faster. ( T / F )
⑤ Every time you throw a ball, you use a pull force to make it move. ( T / F )

① T ② T ③ F ④ T ⑤ F

5. 小宇要在探索营的“巧用力分享会”上讲述他的发现，请选择合适的句子填在横线上，完成发言稿。

My science story
Greetings: ① What I find: ②
How I do it: ③ How I feel: ④
End: ⑤
A. I find that pushing a box on a cart uses a smaller force than on the floor.
B. I borrow a cart from my neighbour to try this smart way!
C. Thank you for listening to my science story!
D. It’s so fun to use forces wisely—small changes can make big differences!
E. Hello! I’m Xiaoyu. Today I want to talk about my smart use of forces.

① E ② A ③ B ④ D ⑤ C