在下面一段文字横线处补写恰当的语句，使整段文字语意完整连贯，内容贴切，逻辑严密。每处不超过15个字。

静和动是一对矛盾，又是一个硬币的两面。人总是静久思动，动久思静。就像旅游，  ①  ，就有出去旅游的冲动。在外面流浪久了，又会有回家的向往。叔本华的“钟摆理论”说，大多数人在需求未得到满足时会陷入痛苦，  ②  。人生就在这痛苦与无聊的两端像钟摆一样摆来摆去。在一切物质需求已达到满足的境况下，能够继续自己对爱与美的不懈追求，  ③  ，这是对一个人极大的挑战。

My favourite shop is called’ Model World’. It is on the second floor of Happy Plaza, near to Pizza Club. It is open from 10 a.m. to 8 p.m. every day.
Model World’ sells all kinds of models. It has model soldiers, cars, boats, airplanes, space shuttles and even dinosaurs. It has models for young children and models for adults (成人). Some models have just about twenty pieces, and others have over 2,000 pieces. You can also buy paints and glue (胶水) and other things there.
The staff at ’ Model World’ is very nice. They are very interested in making models. They will give you advice, and answer all of your questions. The prices are not low but they are not high. My best buy was a model of a helicopter. It cost $ 30 but it had over 400 pieces. It was really fun to make. If you are interested in models, you should visit this shop.

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