The first structures in the universe appear to have formed within
A) the newly formed helium.
B) the normal matter.
C) the electromagnetic radiation.
D) the dark matter.
E) the dark energy.
Question 2
It sure is bright everywhere; you've been able to travel around a bit, and it's clear that you are not in a star. Yet it is as bright as looking directly at the Sun.
In your extensive travels through your current surroundings, you cannot find a single neutral atom anywhere, nor can you find a nucleus besides hydrogen or helium. And, while it is hot (a few thousand degrees Kelvin), it is nowhere near the temperature needed for nuclear fusion. Where are you? A) You are in the universe during its first 300,000 years.
B) You are in the universe more than 10100 years in the future.
C) You are in an accretion disk around a supermassive black hole.
D) You are in the central regions of a quasar.
E) You are where the Sun should be located, but about 5 billion years from now.
Structures of the respiratory tract.
Amino Acids Structures and Diagrams
Three-dimensional structures of proteins: Mixed protein
Summary of major brain structures.
Summary of Structures of the Ear
Structures of DNA nucleotide monophosphates