This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Which of the following is true of wavelengths of signals sent into space? A) Wavelengths longer ... (Read 78 times)

cherise1989

  • Hero Member
  • *****
  • Posts: 555
on: Jul 27, 2018
Which of the following is true of wavelengths of signals sent into space?
 
  A) Wavelengths longer than 100 cm are absorbed in Earth's atmosphere.
  B) The interval between the 21-cm spectral line of neutral hydrogen and the 18-cm line of OH has very high background interference.
  C) Wavelengths longer than 100 cm get lost in the background noise of the Milky Way Galaxy.
  D) The interval between the 21-cm spectral line of neutral hydrogen and the 18-cm line of OH is narrow and can be monitored easily.

Question 2

Which of the following is true of natural selection?
 
  A) It is a random occurrence.
  B) It does not occur in most species of organisms.
  C) It is directed by changes in the environment.
  D) It does not lead to evolution of a species.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Alyson.hiatt@yahoo.com

  • Sr. Member
  • ****
  • Posts: 354
Reply #1 on: Jul 27, 2018
Answer to Question 1

C

Answer to Question 2

C


cherise1989

  • Member
  • Posts: 555
Reply 2 on: Jul 27, 2018
:D TYSM

nguyenhoanhat

  • Member
  • Posts: 332
Reply 3 on: Yesterday
Wow, this really help

« previous next »
 

Did you know?

The most destructive flu epidemic of all times in recorded history occurred in 1918, with approximately 20 million deaths worldwide.

Did you know?

Increased intake of vitamin D has been shown to reduce fractures up to 25% in older people.

Did you know?

Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.

Did you know?

Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.

Did you know?

Urine turns bright yellow if larger than normal amounts of certain substances are consumed; one of these substances is asparagus.

A true albino squirrel. Note the pink eyes. A true albino squirrel. Note the pink eyes.
The urinary system: kidneys, ureters, bladder, and urethra with expanded view of a nephron and the u The urinary system: kidneys, ureters, bladder, and urethra with expanded view of a nephron and the u
True-color image of layers of haze in Titan's atmosphere. True-color image of layers of haze in Titan's atmosphere.
Space Space
Space-Beach Wallpaper Space-Beach Wallpaper
Earth emits radiation back out to space from all surfaces, both day and night Earth emits radiation back out to space from all surfaces, both day and night
Video: Acid-base imbalances - compensation of respiratory acidosis and alkalosis

For a complete list of videos, visit our video library