I'm a doctoral student at University in Japan.

I'm a doctoral student at University in Japan. I've studied X-ray CT, Math, and Programming. In order to satisfy graduation requirements, I have to acquire a high score in the TOEIC test, so I joined this site.

私は博士課程の学生です。大学ではX線CTや数学、プログラミングについて学んでいます。博士課程の卒業要件を満たすには、TOEICで高い点をとらなければいけないため、このサイトに参加しました。

• I'm a doctoral student at University in Japan.
• I'm a doctoral student at a university in Japan.

• I've studied X-ray CT, Math, and Programming.
• I've studied X-ray CT, math, and programming.

• In order to satisfy graduation requirements, I have to acquire a high score in the TOEIC test, so I joined this site.
• In order to satisfy graduation requirements, I have to acquire a high score on the TOEIC test, so I joined this site.

• I'm a doctoral student at University in Japan.
• I'm a doctoral student studying at University in Japan.

• I've studied X-ray CT, Math, and Programming.
• I'm studying X-ray CT, Math, and Programming.

• In order to satisfy graduation requirements, I have to acquire a high score in the TOEIC test, so I joined this site.
• I have to earn a high score in the TOEIC test to satisfy graduation requirements, so I joined this site.

Good job!　　いいですね！

• In order to satisfy graduation requirements, I have to acquire a high score in the TOEIC test, so I joined this site.
• I have to acquire a high score on the TOEIC test in order to satisfy graduation requirements, so I joined this site.

I'm so sorry! I forgot to include changing "in" to "on"
Another user pointed this out, too.