1¡¢Many countries are now setting up national parks ______ animals and plants can be protected.

 A. when            B. which            C. whose            D. where

2¡¢The international situation is currently undergoing great changes ________ UNESCO plays an irreplaceable role in promoting international cooperation.

A. that             B. what                                 C. which             D. where

3¡¢I live next door to a couple ______ children often make a lot of noise.

A. whose            B. why              C. where            D. which

4¡¢The little problems ___________ we meet in our daily lives may be inspirations for great inventions.

A.that                           B.as           C.where       D.when