An ultrasonic distance measurement system for use in air is presented. The measurement is based upon the two-frequency continuous-wave (TFCW) phase-shift method. In the system, two vernier caliper ...

How much English can you learn in a minute? Find out with this series of one-minute videos explaining how to use English. In each episode learn which verbs collocate with a particular noun.

Georgie This video is a great resource for your English learning! Resources are things like time, money or materials that people or organisations can use to function well.

Group sports terms that share a common thread. A new puzzle is available each day.