1. My sister has a vegetarian diet once a week. She wants to live a healthy life.
=My sister wants to live a healthy life; therefore, she has a vegetarian diet once a week
2. Learn some Italian before leaving. You won't make yourself understood there.
=Learn some Italian before leaving;otherwise, You won't make yourself understood there.
3. Italy is famous for pizza. Spaghetti and pasta originate in this country.
=Italy is famous for pizza;moreover, Spaghetti and pasta originate in this country.
4. Kimchi is a famous Korean dish. I don't find it tasty.
=Kimchi is a famous Korean dish; however,  I don't find it tasty.
5. Eat a balanced diet that contains important nutrients. Refrain from eating junk food.
= Eat a balanced diet that contains important nutrients;moreover, Refrain from eating junk food.