7. It takes 1 second to hear the reflection of a loud noise made in front of a large barrier. If the speed of sound in air is 340 m/s, how far away is the barrier?
A. 85 m
B. 170 m
C. 340 m
D. 680 m

colorectal cancer may also develop from areas of abnormal cells in the lining of the colon or rectum. this area of abnormal cells is called dysplasia and is more commonly seen in people with certain inflammatory diseases of the bowel such as crohn's disease or ulcerative colitis.

hi,

what occurs during a solar eclipse?

there are small tides across earth.

the moon is between earth and the sun.

p.s. im not sure if the first answer is correct because during a solar ecliphse there are spring tides and i dont know if they are the same.