7.

Answer and Explanation

Your Answer is

Correct Answer is A

Explanation

Item A: it is the subject of the form, the real subject is to contain..., and the word order is correct.

B item: one that modifies thirty years, semantic error.

Item C: too small, too light modify language, semantic error.

Item D: Lying dormant "dormant" to modify the building blocks, wrong, the language should actually be modified.