Public interest in balloons grows. Inventors develop hydrogen balloons.

A silk balloon filled with hydrogen is launched.

The very first hot-air balloon is launched.

cause

effect/cause

effect/cause

effect

Cause

Explanation:

it keeps you in the air and you can travel having a great source of view and better way to transition in the air with out having an airplane to see and ride.

the unsaturated fatty acid is a fat consist of one or more double bond in the fatty acid chain. if it contains one double bond then called as monounsaturated fatty acid however if, it contains more than one bonds called as a polyunsaturated fatty acid. true fatty acids are called unsaturated fatty acids as it reduces the risk of high blood cholesterol and good for health.

b)and

is the answer.

its because you eat a lot of food and that can lead to many heath problems like diabetes or becoming very over weight and fat etc.