It’s patient our teacher to spend a lot of time things to us patiently.A. of explaining

问题补充：

It’s patient our teacher to spend a lot of time things to us patiently.

A. of, explaining

B. for, to explain

C. for, explainning

D. of, to explain

答案：

(答案→)A. of, explaining

B. for, to explain

C. for, explainning

D. of, to explain

解析：句意：老师花费大量的时间耐心地向我们解释问题，他真是太有耐心了。对于It is+adj+offor sb to do sth句型中介词of和for的选择要遵循的原则就是：当形容词为描述事物的性质时，如important，necessary，helpful和meaningful等用介词for，表示对某人来说做某事是怎么样的；当形容词为描述人的品质时，如kind，nice，stupid等用介词of，表示某人做某事所体现出来的品质。Spend time doing sth意为“花费时间做某事”；故选A。