More and more US students begin to learn Chinese at school ___________ it is very difficult.

A. so                     B. before               C. until                  D. though

阅读下面短文，从所给单词中选出适当单词，并用其正确的语言形式填在标有题号的空白处，使语意通顺完整。(每空一词，每个单词只能使用一次)

      Each year, thousands of Chinese middle school students go to study in foreign countries such as the US, the UK, Australia and Japan.

"Chinese   6  hope very much to go abroad to get a wider view (视野) of the world," said Li Mingshan, a Chinese writer who has lived   7   America for many years. In a talk Li told more than 300 parents and their children that life in foreign countries can be   8  for young people. "They have to meet a culture shock and language problems.”

However, these are not the most difficult things. To most children, looking after   9  when studying alone in a foreign country is a big challenge (挑战).

Zhao Baohua, a 16-year-old student   10  to study in a high school in Australia last October. To his surprise, his teachers there hardly pushed students to study. And usually there wasn't homework. "With these education systems, we have more free   11  and more space for thinking," said Zhao. "But   12  you don't know how to plan your time and money, you will not have an easy time." Some of his friends spent their whole year's money in the first two months of the term, and they didn't   13  their exams.

"Studying abroad at a young age can help students learn foreign languages   14 , but students and parents should know about the challenges," Li said. "If you want to study abroad, try to talk to someone with experience in foreign countries. Make sure that you are   15  for it. "

阅读下面短文，从所给单词中选出适当单词，并用其正确的语言形式填在标有题号的空白处，使语意通顺完整。(每空一词，每个单词只能使用一次)

      Each year, thousands of Chinese middle school students go to study in foreign countries such as the US, the UK, Australia and Japan.

    "Chinese   6   hope very much to go abroad to get a wider view (视野) of the world," said Li Mingshan, a Chinese writer who has lived   7    America for many years. In a talk Li told more than 300 parents and their children that life in foreign countries can be   8   for young people. "They have to meet a culture shock and language problems.”

However, these are not the most difficult things. To most children, looking after   9   when studying alone in a foreign country is a big challenge (挑战).

    Zhao Baohua, a 16-year-old student   10   to study in a high school in Australia last October. To his surprise, his teachers there hardly pushed students to study. And usually there wasn't homework. "With these education systems, we have more free   11   and more space for thinking," said Zhao. "But   12   you don't know how to plan your time and money, you will not have an easy time." Some of his friends spent their whole year's money in the first two months of the term, and they didn't   13   their exams.

    "Studying abroad at a young age can help students learn foreign languages   14  , but students and parents should know about the challenges," Li said. "If you want to study abroad, try to talk to someone with experience in foreign countries. Make sure that you are   15   for it. "