“This book is ______ more useful for us students.” “Yes, but it is _______ too difficult.”

Don’t you think it necessary that he ______ to Miami but to New York？ —I agree，but the problem is ______ he has refused to.

下列各句中，没有语病的一句是（     ）

came in, I saw her sitting in the sofa ______in thought.

下列各句，没有语病的一项是（ ）