(A) rubber

(B) plastic

(C) aluminum

(D) wood

(A) the time of ascent < the time of descent

(B) the time of ascent > the time of descent

(C) the time of ascent = the time of descent

(D) none of these

(A) forward

(B) backward

(C) sideways

(D) none of these

(A) the ringing is not loud enough

(B) the glass of the bell jar absorbs the sound waves

(C) the bell jar is too small

(D) there is no air or any other gas in the bell jar

(A) momentum

(B) velocity

(C) acceleration

(D) inertia

(A) earth and the sun

(B) earth and the moon

(C) Jupiter and the sun

(D) Pluto and the sun

(A) electric current

(B) electric field

(C) acceleration

(D) linear momentum

A) C2H6O

B) HCl

C) Na2CO3

D) NaCl

(A)  cosmic rays

(B) X-rays

(C) radio waves

(D) microwaves

(A) liquid dispersed in gas

(B) solid dispersed in a liquid

(C) liquid dispersed in solid

(D) gas dispersed in a liquid