What device has made car emissions much cleaner? automatic transmission

better wheels

tail pipes

catalytic converters

automatic transmission

Explanation:

An automatic transmission (sometimes abbreviated to auto or AT) is a multi-speed transmission used in motor vehicles that does not require any driver input to change gears under normal driving conditions.

the answer is c.the valence of the atoms combine .

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.