To combine these sentences together to flow neatly and be grammatically correct you could say: Early airships such as zeppelins were filled with hydrogen, but today's blimps use helium instead. This is the correct answer out of your choices.
Your answer is: Early airships such as zeppelins were filled with hydrogen, but today's blimps use helium instead.
Have an amazing day and stay hopeful!
I believe the answer is Person vs. Person
An energetic, playful movement; a <span>gambol.
So in other words. D. </span>
