Problem: OPTIONS:
- enough ' s mass
- solvent's mass
- liquid's mass
- solution ' s mass
Q: Q: The mass percentage of a solution component is defined as the ratio of the component's mass to ________? A:
Answer: solution ' s mass

Problem:OPTIONS:
- gravity
- uteris
- ovaries
- lack of fertilization

Q: What causes the menstrual cycle to be repeated? A:
****
A: lack of fertilization

Q: What is the main organ required for respiration in mammals? A:
OPTIONS:
- the diaphragm
- the heart
- the brain
- the lungs
the lungs

Q: The most common two-lens telescope, like the simple microscope, uses lenses of what shape? A:
OPTIONS:
- concave
- angular
- cylindrical
- convex

Answer: convex

Question: Q: What is the movement of animals from one place to another called? A:
OPTIONS:
- evacuation
- hibernation
- extinction
- migration
Answer: migration

input: OPTIONS:
- the complex envelope
- the cell wall
- the nuclear compression
- the nuclear envelope Now, answer this question: Q: What is a double membrane of the nucleus that encloses the genetic material? A:
A:
output:
the nuclear envelope