来自孙克勤的问题
英语句子结构问题Hehasbeenabletotellusmoreabouttheactivevolcanoesthananymanalive.知道wereableto意思.为什么是hasbeen,
英语句子结构问题Hehasbeenabletotellusmoreabouttheactivevolcanoesthananymanalive.
知道wereableto意思.为什么是hasbeen,

