Dùng từ đã cho viết thành câu hoàn chỉnh 1.All sounds are not noise.Noise is any sound that is unwanted and goes beyond its certain limit,for example,abive 80 decibels (because) =>......................... 2.More and more noise is created by modem civilization.It has now become a major environmental pollutant,especially in urban areas. (So) =>....................... 3.Contamination in the air happens.There is acid rain which damages soil,vegetation and aquatic life of the region. (Causes) =>....................... 4.Water pollution gets more serious in the future.It affects the development of economy and society. (If) =>......................... 5.The soil is poisoned because farmers use too many pesticides and herbicides. (If) =>..........................