Cause of the invention of the cell phone

Cooper wanted people to have freedom to talk on the phone away from their cars. So in reaction, he and Motorola embarked on a project to create a more portable device. ... Martin Cooper placed what's recognized as the first public cell phone call in New York City in 1973

plz help me answer my question too

Explanation:

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'

i might look it up later.