as a quicker or shorter way of saying something
Example: My name is Reginald, but you can call me Reg for short.
The short form of because ('cause) is spelled with an apostrophe before it to indicate the missing letters and distinguish it form the word cause, which has a different meaning and pronunciation. Follow the link to find out more.
more information: 'cause
Culture shock is the unhappiness and unease caused by not understanding a different society with different expectations.
Example: I felt some culture shock when I went overseas to study.
To have eye contact is to look directly at another person's eyes while they are looking at your eyes.
Example: I thought he was lying because he wouldn't make eye contact.
Here taught is the past participle of the irregular verb teach. Follow the link to find out more and to listen to examples.
more information: teach