Question

because, but, & so - american sign language it can be difficult to determine the number of people who use american sign language (asl) the united states census does not collect data on asl. because but so ← joining words screenreader users: make sure to read through the whole sentence before filling in the blanks. fill in the blank with the correct joining word.

Explanation:

The second clause explains the reason for the difficulty stated in the first clause. "Because" is used to introduce a cause or reason, which matches the logical relationship here. "But" indicates contrast, and "so" indicates a result, neither of which fits the context.

Answer:

because