I don't see anything wrong with traveling
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!
Edmund Husserl (1859—1938) was an influential thinker of the first half of the twentieth century. His philosophy was heavily influenced by the works of Franz Brentano and Bernard Bolzano, and was also influenced in various ways by interaction with contemporaries such as Alexius Meinong, Kasimir Twardowski, and Gottlob Frege.
Answer:
this is a personal question. Think of a time that you were scared but refused to quit; that is what bravery means.