I even had the lecture translated into Mandarin to avoid any claims of mistranslations from my English-proficient students.
我甚至将讲话内容翻译成中文，以免我那些通晓英语的学生声称存在误译的情况。
2
The children of immigrants tend to be bilingual and proficient in English, "by the third generation, the original language is lost in the majority of immigrant families".
移民的孩子往往会说两种语言，而且精通英语，“到了第三代，大多数移民家庭都丧失了原来的语言。”
3
Yet most black South Africans are not proficient in English.