【正确答案】:
TODAY, WITH CONTINUOUS IMPROVEMENT OF THE ECOLOGICAL ENVIRONMENT, MORE AND MORE SPECIES OF BIRDS DWELL IN BEIJING. 
【题目解析】:本题考点:介词的正确使用。as表“伴随,随着”的意思时为连词,连词后面要接句子。所以把连词as改成介词with后面加名词。
TODAY, WITH CONTINUOUS IMPROVEMENT OF THE ECOLOGICAL ENVIRONMENT, MORE AND MORE SPECIES OF BIRDS DWELL IN BEIJING.