Many provinces in China were attacked by such terrible snowstorms this early winter ________ few people had experienced before, ________ made us worry about global climate changes．

1. A.
   that; that
2. B.
   as; which
3. C.
   which; it
4. D.
   when; as

 Many provinces in China were attacked by such terrible snowstorms this early winter ______ few people had experienced before, ______ made us worry about global climate changes.

   A. that; that      B. as; which         C. which; it        D. when; as

Many provinces in China were attacked by such terrible snowstorms this early winter ______ few people had experienced before, ______ made us worry about global climate changes.

     A．that; that            B．as; which      C．which; it        D．when; as

Many provinces in China were attacked by such terrible snowstorms this early winter ______ few people had experienced before, ______ made us worry about global climate changes．

A．that; that      B．as; which          C．which; it        D．when; as

 Many provinces in China were attacked by such terrible snowstorms this early winter ______ few people had experienced before, ______ made us worry about global climate changes．

     A．that; that         B．as; which          C．which; it            D．when; as