statement
2007.8.12 7:53:32
He instructs us in chemistry!√---〉软键盘--〉数学符号
He teaches us chemistry!√no need the word " in"
He instructs us chemistry!×
He instructs us in chemistry!√---〉软键盘--〉数学符号
He teaches us chemistry!√no need the word " in"
He instructs us chemistry!×
