15．– How cold it is! I wonder how grass survive under such heavy snow．

--Don’t worry．There is a lot of air in loose snow which _______．

15．– How cold it is! I wonder how grass survive under such heavy snow．

       --Don’t worry．There is a lot of air in loose snow which _______．

       A．keeps out the cold         B．keeps the cold away

       C．keep off the cold            D．keep the cold up

15．– How cold it is! I wonder how grass survive under such heavy snow．
--Don’t worry．There is a lot of air in loose snow which _______．

 – How cold it is! I wonder how grass survive under such heavy snow．

    --Don’t worry．There is a lot of air in loose snow which _______．

    A．keeps out the cold               B．keeps the cold away

    C．keep off the cold                D．keep the cold up