<span>gills; lungs
Sharks have spiracles, also for whales they have lungs. Moreover look at amphibians, they live near water sources because they need an area where they can lay and protect their eggs. The early stages of an amphibian's life is spent mostly underwater. This is where they mature and slowly develop into land organisms. In the early stage of their life, they breathe through their gills and they do not have limbs yet. As they grow gradual changes in their body structures are prominent, this process if called metamorphosis.</span>
In general terms, “sex” refers to the biological differences between males and females, such as the genitalia and genetic differences. “Gender” is more difficult to define, but it can refer to the role of a male or female in society, known as a gender role, or an individual's concept of themselves, or gender identity.
a control helps to increase the reliability of the results. it allows a scientist to compare it to other group(s) in an experiment. if a scientist notices a significant different btwn the control and the other groups, he can logically conclude that the independent variable has an impact on the dependent variable.
a variable is any factor, trait or condition that can exist in differing amounts or types. there are usually three tpes of variables in experiments: the independent, dependent and contolled. the independent variable variable is the one that is changed by the scientists to figure it's affect on something.
if you were making an observation of two substances, The five conditions of chemical change would be color chage, formation of a precipitate, formation of a gas, odor change, temperature change. i hope this helps
Answer:More soldier who had lost a limb returned home.
