I think the answer is right but I’m not ____ sure about it.
China's icebreaker Xuelong ______ by heavy floes since Friday after rescuing passengers on a Russian vessel stranded in Antarctica.
The sign _____ “In case of _______ fire, break the glass and press _______ red button.”
— Hi, John! I’m going to Greece for my holiday.— Greece? A splendid country, ______ well worth visiting.
— The government requires that every primary school student do sports for at least one hour every day.— _____. It is high time that students took exercise in order to build a strong body.
—Have you ever seen two leaves that are exactly the same?—Never. Leaves differ ____ each other ____ size and shape.