孩子们用金属零件套装搭建了一个小型风车。

The kids built a small windmill with their ___Meccano pieces.

这个城市的交通系统就像一套复杂的拼装玩具，各部分紧密相连却又难以理解。

The city's transportation system is like a ___Meccano set—intricately connected yet hard to comprehend.