Many scientists believe that robots ______ able to talk like humans in 50 years.
A．were B．are
C．will be D．have been
— Why does the earth look blue in space?
— Because most of the earth’s surface ______ by water.
A．covers B．is covered
C．cover D．are covered
Look! The model is walking to us. ______ nice dress!
A．What B．What a
C．How D．How a
— What were you doing ______ I knocked at the door?
— I was sleeping.
A．unless B．once
C．when D．while
Mount Xiaolei is not far away from here, but it will still take us a few hours ______ there by bike.
A. getting B. to get
C. got D. get
— Hi, Sara. Is this ______ English book?
— No. ______ is on the desk.
A．your； Mine B．your；My
C. yours；Mine D．your；My
