"Isn't" is the best option from the list in terms of completing these sentence. This is primarily because "isn't" is a contraction of the two words "is" and "not.
Answer:
I don't get this problem,please give me more information so I can help you.
Explanation:
It is 4. because it says in the paragraph and I quote: "helium has a very low density. it is used in daily weather balloons to carry instruments that record, tempature, humidy, and pressure readings in the atmosphere.
What play and scene is being referred to?
