1 . Thirty percent of air in the city ________ (pollute) so far. (所给词的适当形式填空)

2 . To our shock, the young girl struggled________________ (support) a large family last year, which ________________   (appreciate) by her family members. (所给词的适当形式填空)

3 . Though ________________ (major) in engineering, the lady made every effort to learn calligraphy which ________________ (regard) as an art form. (所给词的适当形式填空)

4 . The programme last week ________ (organise) by the lecturer, which aroused many people’s   ________ (curious). (所给词的适当形式填空)