施工队正在加固建筑物的基础结构以确保安全。

The construction crew is reinforcing the building's ___substructures to ensure safety.

这座大桥的支撑结构经过特殊设计以确保安全。

The ___substructures of this bridge were specially designed to ensure safety.

语法分析需要识别句子中的子结构。

Grammatical analysis requires identifying ___substructures within sentences.