There are many volunteers in our town.
Some volunteers are working in homeless shelter.
Earthquake is scary.
Flood indicates that it rained too much.

==========================

1.
Stina: There are many volunteers in our town.
Correct: NO CORRECTION

2.
Stina: Some volunteers are work in homeless shelter.
Correct: Some volunteers are working in homeless shelter.
*PRESENT PROGRESSIVE TENSE
Use a linking verb (is/are) with the main verb in -ing form.
Examples: 
                  subject + linking verb + main verb in -ing form
                    She is studying.

3.
Stina: Earthquake is scary.
Correct: NO CORRECTION

4.
Stina: Flood means rain too much.
Correct: Flood indicates that it rained too much.
Explanation: 
*Use the word indicate to show that something exists.
*Use the word mean when asked for the definition. 

==========================

Hello, Stina! Thank you for submitting your homework. Please read the following corrections and explanations carefully. If you have questions and clarifications, you can ask me in our class. Thank you!