This paper tries to introduce the developing history of LWD technology and the features of respective periods, as well as the service abilities and advantage

The paper deeply inquires into the reason about discarding analog filter from nowaday instruments in respects of seismometer developing history, theory of analog filter, principle of reflecting wave and viewpoint.

The developing history of farmers courtyard economy can be devided into four perieods—begining,forming,consummating and developing.

Revelation of function teaching about history of function concept;

Research into the History of American Educational Technology;

History Development of Private International Law and Enlightenment to the Present Age;