4.第一次看Gangnam Style的时候，其生动的节奏，富有创意的舞蹈，给我留下了深刻的印象。（The first time）
1.We benefited a lot from the three-day social practice. / The three-day social practice benefited us a lot.
2.To our relief, the government is taking measures/action to improve our housing conditions.
3.Despite many difficulties / In spite of many difficulties, he never gave up his desire to become /be an excellent / outstanding / a distinguished architect.
4.The first time I watched Gangnam Style, I was deeply impressed by its lively rhythm and creative dance. / its lively rhythm and creative dance impressed me a lot / deeply / greatly.
5.The air quality in some big cities is getting / becoming from bad to worse, which should alert us( to the fact) that the lack of environmental awareness has come at the expense of the health of the citizens. / the lack of environmental awareness (lacking environmental awareness) has cost the citizens their health. / ...that the citizens have paid ( high) price for the lack of environmental awareness.