Transform the following Sentences as directed: (a) The birds that come to our country in time of winter are called guest birds.(Simple) (b) As they can not tolerate the severe cold in their native land, they come to a temperate country like Bangladesh. (Compound) (c) They come to our country to search a better shelter. (Complex) (d) They perform an important role to balance the environment. (Passive) (e) They cannot but fly far away from our country. (Affirmative)