measure为什么不用被动语态

在你的句子中，measure是系动词，意思是“有…尺寸”“量起来其体积（面积、长度、数额等）为…”，此时它是不能用被动语态的。

从汉语的意思来考虑，这样用的 measure 确实有被动意味，但由于它是系动词，是不能用于被动语态的。但若用作及物动词表示“测量”，则完全可以用于被动语态。如：

A ship's speed is measured in knots. 船速以节测量。

Cloth is measured in metres. 布料以米计量。

The school’s performance is measured against a strict set of criteria. 学校的业绩是以一套严格的标准来衡量的。

The rainfall was measured over a three-month period. 对三个月内的降雨量进行了测量。

类似地，用作连系动词的look, sound, smell, taste 等也含有被动意味，但它们也不能用于被动语态。如：

正：She looks beautiful.

误：She is looked beautiful.

正：The explosion sounded horrible.

误：The explosion was sounded horrible.

正：The soup smells / tastes nice.

误：The soup is smelt / tasted nice.