How does an atom become a positive ion? A- It loses an electron,
B- It gains an electron,
C- It gains a neutron,
D- It loses a neutron

Nasa scientists must work together to make sure that everything is correct and accounted for when launching a shuttle. besides a physicist, what other type of scientist would be in making sure that the shuttle has the appropriate type and amount of fuel to reach its destination?

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures

Which are characteristics of flukes? check all that apply. a they are free living. b they are a type of flatworm. c they reproduce sexually. d they have eyespots. e they are segmented.