Sadler was an outstanding scholar in comparative education in the late 19th century and early 20th century, who made a great deal of pioneering work in his lifetime.是什么意思_Sadler was an outstanding scholar in comparative education in the late 19th century and early 20th century, who made a great deal of pioneering work in his lifetime.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句