Which of these is a disadvantage of hydrogen fuel?
o
a. it is expensive to produce and transport.
o
b. it works in'efficient, clean engines.
o
c. it is useful for generating electricity.
o
d. it is a continually available energy source.

As the pea seeds respire, the level of coloured liquid in the left hand part of the capillary tube rises. by referring to what is happening in the apparatus, explain why the level of liquid changes

Sort the examples by the type of diversity that they exhibit a park has 80 species of trees red, yellow, and orange bell peppers are all members of the same species individuals of the same lizard species have different mating strategies. five different bird species are at a bird feeder. genetic diversity species diversity

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from