two细节题。根据“There are often two different types of health insurance you can consider buying”可知正确答案。

Obtaining good health insurance is a real necessity while you are studying overseas. It protects you from minor and major medical expenses that can wipe out not only your savings but your dreams of an education abroad. There are often two different types of health insurance you can consider buying, international travel insurance and student insurance in the country where you will be going.
     An international travel insurance is usually purchased in your home country before you go abroad. It generally covers a wide variety of medical services and you are often given a list of doctors in the area where you will travel who may even speak your native language. The drawback might be that you may not get your money back immediately, in other words, you may have to pay all you medical expenses and then later submit your receipts to the insurance company.
     On the other hand, getting student health insurance in the country where you will study might allow you to only pay a small percentage of the medical cost at the time of the service and thus you don’t have to have sufficient cash to pay the entire bill at once. Whatever you decide, obtaining some form of health insurance is something you should consider before you go overseas. You shouldn’t wait until you are sick with a major medical bills to pay off.