Chemical pollution will bring about a threat to agriculture and food chain, andto human health.

She put some soil in the box, then sowed the seeds carefully, and covered it with more soil. _______ she kept the box in the shade.

Maggie has been fortunate to find a job she loves; __________，she gets well paid for it. 

—In early autumn Steve applied for admission to college. He wanted to go      but to Cornell University.—Oh, why not Harvard?

Unsatisfied       with the payment , he took the job just to get some work experience .