这里Hollow as it is中的as意为“因为”

有一读者问: 这样一道选择题:

(1)______________as it is, bamboo is very light.

A. Empty B. Space C. Hollow D. Thick

我认为应选D,因为as在此应作“虽然”解,而答案却是C,不知是何缘故?

在上述句(1)的句型中,as的确常作“虽然”解,如:

(2)Young as he is, he is able.

但as有时亦可作“因为”解,上述句(1)中的as即作此解,故应选C,再如:

(3)Young as he was, it is natural that he should have acted so foolishly.