C. Must B. Everyone has arrived. C. Get the main idea C. Ex

Here are the answers to your questions:

8. C. Must A modal verb is an auxiliary verb that expresses necessity, possibility, permission, or ability. "Must" indicates necessity. "Run" and "Eat" are main verbs. "Book" can be a noun or a main verb.

9. B. Everyone has arrived. The indefinite pronoun "Everyone" is singular and requires a singular verb. Therefore, "has arrived" is the correct concord.

10. C. Get the main idea Skimming is a reading technique used to quickly read through a text to get a general overview or the main idea, rather than focusing on specific details or memorizing content.

11. **C. Ex