Answer:
1. At 9:10 this morning, we'll be leaving for the natural history museum.
2. Please bring the following materials with you: pencils, paper, erasers, and a notebook.
The bus will be back at 4 am to pick us up. (it doesnt need one)
4. The special exhibit on birds contains the following types prehistoric birds: seabirds, and domestic birds.
5. The letter we wrote to the museum began: "Dear Sir, Please let us know when the special exhibition on penguins will be shown at your museum."
If you don't understand reread the question ahain and again
Helping verb because it is before the main verb and is HELPING the sentence make sense. Without 'has' the sentence will be My brother eaten all the chili in the pot. That doesn't make sense
Hope that helped!