so it is often difficult to tell whether they are boys or girls.中的difficult to tell whether是什么

His writing is so confusing that it is diffi In summer,it is very hot here.So we often have cold() to keep. It often rains here in summer.So summer is the w_ season here. There is only one computer in his home,so he often s_____ it with his family so it is often h___to toll whether they are boys or girls City air is dirty,so it would be wise of you to wash your hair often so it is wise for you to shampoo your hair often翻译 And it is often r[ ]. so it is with it is so ( ) It is so Linhai is near the sea,so the weather is always sunny.It doesn't often rain or snow. It is very cold .It often ___heavily so it is often difficult to tell whether they are boys or girls.中的difficult to tell whether是什么 ：A：---- B：Yes,I think so.Milk is good for our health and we need to drink it often. 请高手赐教：So it is often hard to tell whether they are boys or girls.的中文意思 提问so it is often hard to tell whether they are boys or girls.的中文意思 The problem is so difficult that she could ____work it out. A.hardly B.usually C.still D.often