The mineral selenium is very poisonous, which ________.
A) means that any selenium in our diet is a bad thing
B) tells us that it must be inorganic
C) doesn't mean it might also be a very essential ultratrace mineral
D) suggests that it is a potent allergen
Question 2
Two of the most abundant minerals in our diet are ________.
A) ions
B) atoms
C) molecules
D) non-metals