美國總統特朗普表示，美軍已擊沉10艘伊朗海軍軍艦，並「大致摧毀」其海軍總部。
휘발유 1713.7원, 환율 1466.1원…중동發 물가 불안 커진다，更多细节参见体育直播
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货郎图早见于南宋李嵩所绘，其传世作品有4幅，尺幅都较小。明代继承并发展了这类绘画主题。目前所见，明代货郎图有近20件，其风格样式与南宋画作有所区别：一是尺幅变大，其几乎全为挂轴形制，当系悬挂张贴装饰之用；二是设色艳丽，货郎衣着华贵；三是发展出了成组的四景货郎图，或只表现单一品目（如鸟类）的货郎图。。heLLoword翻译官方下载对此有专业解读
Often people write these metrics as \(ds^2 = \sum_{i,j} g_{ij}\,dx^i\,dx^j\), where each \(dx^i\) is a covector (1-form), i.e. an element of the dual space \(T_p^*M\). For finite dimensional vectorspaces there is a canonical isomorphism between them and their dual: given the coordinate basis \(\bigl\{\frac{\partial}{\partial x^1},\dots,\frac{\partial}{\partial x^n}\bigr\}\) of \(T_pM\), there is a unique dual basis \(\{dx^1,\dots,dx^n\}\) of \(T_p^*M\) defined by \[dx^i\!\left(\frac{\partial}{\partial x^j}\right) = \delta^i{}_j.\] This extends to isomorphisms \(T_pM \to T_p^*M\). Under this identification, the bilinear form \(g_p\) on \(T_pM \times T_pM\) is represented by the symmetric tensor \(\sum_{i,j} g_{ij}\,dx^i \otimes dx^j\) acting on pairs of tangent vectors via \[\left(\sum_{i,j} g_{ij}\,dx^i\otimes dx^j\right)\!\!\left(\frac{\partial}{\partial x^k},\frac{\partial}{\partial x^l}\right) = g_{kl},\] which recovers exactly the inner products \(g_p\!\left(\frac{\partial}{\partial x^k},\frac{\partial}{\partial x^l}\right)\) from before. So both descriptions carry identical information;