这一证据站不住脚，既薄弱又缺乏实质。

The evidence is ___tenuous, weak and insubstantial.

反对意见是脆弱的，缺乏坚实支持。

The objection is ___tenuous, lacking firm support.

蜘蛛丝看起来非常纤细脆弱。

The spider's silk appears extremely ___tenuous and fragile.

他们之间的关系很脆弱，仅仅建立在几次偶然的相遇上。

Their relationship is ___tenuous, built only on a few chance encounters.