Aseries of connections of food chain in an ecosystem is called a what

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons

In which squares should the phrase "green pods" appear a) a and d b) b and e c)a,c, and d d)a,b,c,d and e

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above