The most common organisms with exoskeletons are arthropods which include insects (bees, ants), arachnids (spiders) and crustaceans (lobsters and crabs).
Dystocia refers when a birth is difficult.
After the Big Bang happened, the universe is constantly expanding. The Universe has expanded for around 13.7 billion years. The further a galaxy is, the faster it would move away from Earth. This principle is called the conservation of momentum.