再次麻烦一下这是什么高中语法,麻烦告诉下

再次麻烦一下这是什么高中语法,麻烦告诉下
[高考考例]2.In the dark street,there wasn’t a single person _____ she could turn for help.[MET 1992]
A.that B.who C.from whom D.to whom
[思路点拨]答案为D.turn to sb for help 为固定搭配表示“求助于某人”
（2）以先行词与从句中的动词关系及所表达的含义而定或以先行词在定语从句中的作用与含义而定.
[考例]1.The medicine of science,______ progress has been very rapid lately,is perhaps the most important of all the science.
A.to which B.in which C.which D.with which
[思路点拨]答案为B.从句主谓结构搭配为：progress has been rapid in,这里的in意为“在某方面”,相当于rapid progress has been made in the science of medicine.
[考例]2.The professor made his first speech _____ he talked about some subjects the students were interested.
A.that B.which C.in which D.of which
本人英语不太好我想提前为高考做准备这是什么语法呢?给个名字就行了我自己上网查谢谢各位老师了!