"Those kind/sort of questions are very difficult" (那种题目非常困难)are common in speech but are thought by teachers to be incorrect. 上述这类句子常用于口语中,但教师们却认为这种用法不正确。In writing it is better to use this form 在写作时最好是用以下的形式:"That kind/soft of question is very difficult" or 或 "Questions of that kind/sort are very difficult".