They _____ each other. They have been deskmates in science class for the last 3 months!

1. They _____ each other. They have been deskmates in science class for the last 3 months!
2 The _____ system protects your body from bacteria, viruses, fungi, and toxins
3. 
The package _____ more than a week ago, but it _____ until yesterday.
4. Could you speak _____ , please? I don't understand you
5. I get very _____ when I can't find the words to express what I mean. It's so _____