高中英语单选1 -What does the notice say?-All the storytellers shou

高中英语单选
1 -What does the notice say?
-All the storytellers should meet at the same hall___won the first three prizes
A.what B.as C.who D.which
2.You can't imagine the difficulty I have ___the problem
A.to solve B.solved C.solving D.solve
3.When you read the renference book,you'd better make a mark___you have any doubts.
A.which B.in which C.where D.in where
4.Beijing,____for hosting the 2008 Olympic Games ,___its first loop of green belt around the dountown,
___an area of 102.3 square kilometers,in the past three years.
A.prepared;built;covered B.preparing;built;and covered
C.which prepares ;building;covers D.preparing;built;covering