tightrope

1.1859 Charles Blondin made the earliest crossing of the Niagara Falls on a tightrope.

查尔斯·布隆丹第一次走钢索跨越尼亚加拉瀑布。

2.I’m walking a tightrope at the moment; one more mistake and I might lose my job.

我现在处境不妙，再犯一个错误就会被开除。