Listen! Helen is singing in the next room.– It be Helen. She has gone to Guangzhou.

下列各句中，没有语病的一句是

Mary was crying sadly. — Oh, she ________ the bad news that her mother was badly injured in the accident.

Are you _______ to go hiking with us— Yes, I _______.

It is no doubt that once ____ this city, you’ll find that there is so much surprise waiting for you to discover.