Stop carrying the weight of the world on your shoulders.
别太操心了,没有你地球照样转。 (carry the weight of the world on one’s shoulders:自以为重任在肩。)
and we have only to turn to that extraordinary discovery of echo-location in bats to see a case in which the voice plays a strictly utilitarian role.
我们只要看一看蝙蝠回声定位这一极不寻常的发现,就可以探究一下声音在什么情况下有绝对的实用价值。