河北省正定县2015高考英语暑假练习（10）（答案或解析）
阅读下面短文，从每题所给的四个选项(A、B、C和D)中，选出最佳答案。
Science can't explain the power of pets, but many studies have shown that the company of pets can help lower blood pressure (血压) and raise chances of recovering from a heart attack, reduce loneliness an
