Listening is the communication means used with supreme frequency, and the ability to listen is most essential for people to communicate.
听是人类使用频率最高的交际手段，听话能力是人们最必需的交际能力。
2
Elephants may be listening with their feet as well as with their ears, say researchers who are studying how well super-low frequency elephant song moves through the ground.
大象在用耳的同时，还能用脚倾听——研究大象超低频鸣叫地面传播的研究人员如是说。
3
Take into account when people stop listening when the frequency of high-frequency ultrasound has just begun.