the key to后用and连接两个ving作to的宾语，and后需不需要加to？

具体语境为：Pronunciation is the key to learning another language and to making yourself understood by native speakers. 句中的第二个to能否去掉？

赞同陈老师的解答。又如：

Both Israel and the U. S. see Mr. Abbas as the key to reviving the peace process and ending more than five years of bloodshed.美国和以色列都把阿巴斯看作是恢复和平进程、与结束5年多流血冲突的重点人物。