想必現(xiàn)在有很多小伙伴對(duì)于Yesterday our headmaster made a speech ______ environmental protection， and we learned something about recycling of waste．（　?。〢.onB. atC. to","title_text":"Yesterday our headmaster made a speech ______ environmental protection， and we learned something about recycling of waste．（　?。〢.onB. atC. to方面的知識(shí)都比較想要了解，那么今天小好小編就為大家收集了一些關(guān)于Yesterday our headmaster made a speech ______ environmental protection， and we learned something about recycling of waste．（　　）A.onB. atC. to","title_text":"Yesterday our headmaster made a speech ______ environmental protection， and we learned something about recycling of waste．（　　）A.onB. atC. to方面的知識(shí)分享給大家，希望大家會(huì)喜歡哦。

on"關(guān)于、在…之上、在…時(shí)候"；to"朝、到、對(duì)于"；at"在、以、向"，三者都是介詞．．由題干"昨天我們的校長(zhǎng)發(fā)表了關(guān)于環(huán)境保護(hù)的演講，我們學(xué)到了一些回收廢物的方法．"可知。

空格是"關(guān)于"，用on，因此答案應(yīng)是on．故選：A．。

本文到此結(jié)束，希望對(duì)大家有所幫助。