Question

question 18 based on the best scientific data and models, astronomers now think that the universe is: open, expanding, but decelerating closed, expanding, and accelerating flat, expanding, and decelerating open, expanding, and accelerating flat, expanding, but accelerating

Explanation:

Current astronomical data (e.g., from cosmic microwave background and supernova observations) shows the Universe is flat (critical density), expanding, and its expansion is accelerating due to dark energy.

Answer:

flat, expanding, but accelerating