_____did the space flight last? —Twenty-one hours.[ ]

I don’t remember when and where I this umbrella.

Do you know the girl ______ is standing under the tree ?—She is my little sister.[ ]

_ _Don’t__________ too late, or you will feel tired in class tomorrow. _ _I won’t, Mom. Good night.

Where is Jack? — In the sitting room. He _______ TV with his brother.