例句與造句

1. The oval cross-section of the upper shaft gradually transforms into a rounded D-shape at mid-shaft, with the long axis of the cross section extending transversely.
2. The Dr . I was a single seat triplane developed at the same time as the Siemens-Schuckert D . II . It used the flat sided fuselage of the earlier Siemens-Schuckert D . I biplane rather than that of the rounded D . II . Like the D . I the Dr . III was powered by a Siemens-Halske Sh . I nine cylinder rotary engine.
3. It's difficult to find rounded d in a sentence. 用rounded d造句挺難的