Fill in the blanks with as ... as, so ... as,

Fill in the blanks with as ... as, so ... as, than.
1.The climate of the central part of Russia is not ... cold ...
that of Siberia.
2.The weather in early autumn is often ... warm ... in summer.
3.In winter days are shorter ... nights.
4.Spring here is more pleasant... autumn.
5.You speak English ... fast ... I do.
6.Was it... frosty yesterday ... it is today?
7.This book is n o t . . . interesting ... that one.
8.Your room is not ... dark ... mine.