最近在准备考雅思刷真题，剑桥真题第11册的test 1 reading passage 2的17题有问题。
题目是
The Falk Wheel is the only boat lift in the world which has steel sections bolted together by hand.
答案是no given
精解写说在第4段最后，
over 45,000 bolt holes were matched with their bolts, and each bolt was hand-tightened.
说明题目后半段是对的，但未提及是不是 the only boat lift.
所以答案是no given.
可是这篇文章的第一句
The Falk Wheel in Scotland is the wold's first and only rotating boat lift.
不是已经说它是世界上唯一的吗？
为什么不是true?