Translate each of these quantifications into English and determine its truth value.
a) \(∃x∈ℝ (x³ = -1)\)
b) \(∃x∈ℤ (x¹ > x)\)
c) \(∀x∈ℤ (x - 1 ∈ ℤ)\)
d) \(∀x∈ℤ (x² ∈ ℤ)\)