What effect has modern technology had on medicine（）
A. It has reduced the costs of medical treatment.
B. It has helped save the lives of most patients.
C. It has encouraged doctors to do more heart surgeries.
D. It have helped educate people about the prevention of heart disease.
What would be the best title for the passage （）
A. The Greatest Killer in the West
B. Heart Disease: Treat or Prevent
C. Modern Technology and Heart Surgery
D. Heart Surgery: Advantage and Disadvantages
碳弧气割是利用碳极电弧的高温，把金属局部加热到熔化状态，同时用( )把熔化金属吹掉，从而达到对金属进行切割的一种加工方法。
A. 压缩空气的气流
B. 压缩氧气的气流
C. 高压水流
D. 等离子气流
38（）
A. paper
B. papers
C. news
D. stories
微信支付 
支付宝支付