Please help me:)

Which of the following statements is true?

Mars' moons may be captured comets.
Comets have circular orbits around the sun.
Chunks of rock that hit Earth's surface are called asteroids.
Most meteors burn up in Earth's atmosphere.

Which statement describes an endocrine function rather than an exocrine function? a. salivary glands release saliva into the mouth. b. sweat glands release sweat onto the skin c. the pineal gland releases melatonin into the blood. d. esophageal glands release mucus into the esophagus.

The chromosomal structure that limits the number of cell divisions of a cell is the the chromosomal structure that limits the number of cell divisions of a cell is the kinetochore telomere histones centromere

Which scientific design has both practical limitations and limitations due to scale? studying the effect of bleach on the growth of mold spores exposing cultures of duckweed to different intensities of light observing the replication of dna molecules with a hand lens using colored marbles to model a cross between two colors of rabbits