Unit one A World inside Unit Two Though the eyes of a child travelling across the United States with no real Unit three The living arts Unit Four the United States, eg a bank, a marketing research
underground['^ n d agr a u n d]a.地下的 via['vaia]prep.经过,通过 keyboard[ki:b:d]n.键盘 visual[' vi zj ual]a.视觉的,光学的 originate[a' r i si ne i tJv.发生,开始 originating call发端呼叫
Strain energy and potential energy of a beam brec sedans hoMe the neutra xxis remain So Figure 1: Kinematic assumptions for a beam Kinematic assumptions for a beam: From the figure: AA'=u3(a1) Assume small deflections: B B\,BB\=3+ duy
Any periodic waveform f(t)f(t) can be expressed by a Fourier series provided that (1) If it is discontinuous, there are only a finite number of discontinuous in the period T (2)It has a finite average value over the period T (3)It has a finite number of positive and negative maximums in the period T