Hello! I'd be happy to help you with your question.
Doodlebob can create a function that takes in a 1D array and erases every element of the array except for the first two elements in the following way:
```python
def keep_first_two_elements(array):
return array[:2]
```
This function takes in an array as its input and uses slicing to return only the first two elements of the array. Slicing is a technique used in Python to select a range of items from a sequence (e.g. list, tuple, or string).
So, when Doodlebob calls the function and passes it in the 1D array, it will only return the first two elements of the array.
For example:
```python
arr = [1, 2, 3, 4, 5]
print(keep_first_two_elements(arr))
```
This will output:
```python
[1, 2]
```
I hope that helps! Let me know if you have any further questions.