Question

it being a rainy day ,he did not go out for a walk 为什么用it being 求解，详细点。谢谢

Answer 1

独立结构！这样可以不用连词连接两个句子！如果用it was ，那么就得用so he ……加连词so

Answer 2

独立主格结构，貌似是的。