The material used as a biological sensor is one dimension of 20 mm, the other Are in nanometers

May someone me with these science questions

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

Total the mass on the syringe. record it in the correct row of the data table. kg done click and drag weights to change the pressure. click the syringe to zoom in and see the volume. intro