Why does sound need a medium to travel?
A. The particles transfer energy through direct contact.
B. The particles slow down.
C. Empty space makes the sound travel faster.
D. Sound does not need a medium to travel.

Sam hated the long nights of winter! his mother called him in from playing so early: around 4: 30 pm! it is usually dark out when sam is eating supper. what letter represents the long nights where sam lives? a) a. b) b. c) c. d) d.

The creation of the european union has had all of the following effects except

The us labor movement began in the a. 1930s b. 1920s c. 1880s d. 1860s select the best answer from the choices provided. a b c d