—It’s meaningful us to do something for people in need—It’s really nice you to think so．A

—It’s meaningful us to do something for people in need．
—It’s really nice you to think so．
A. for; of
B. of ; for
C. for; for
D. of; of

(答案→)A. for; ofB. of ; forC. for; forD. of; of解析：句意：对我们来说为有需要的人做些事情是有意义的。你能这么想真是太善良了。对于It is+adj+to/for sb to do sth句型中介词to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。故选A。

这个解释是对的