A. triangle B. rectangle C. pentagon D. circle 相关知识点: 试题来源: 解析 D。圆形是对称图形,它有无数条对称轴。三角形分为等边三角形、等腰三角形和一般三角形,只有等边三角形和等腰三角形是对称图形;长方形有两条对称轴;五边形不一定是对称图形。反馈 收藏 ...
Look at these shapes. Which one is symmetrical? A. A leaf B. A pentagon with unequal sides C. An oval D. A kite 相关知识点: 试题来源: 解析 C。解析:椭圆形是对称图形,有对称轴。选项 A 叶子通常不对称;选项 B 边长不等的五边形不对称;选项 D 风筝一般不对称。
Read our sunglasses style guide and find which shades suit your face shape. From wayfarer frames for heart shapes to aviator sunglasses for oval faces and more.
Fig. 3 shows such a nozzle, the welding occurring at 6 and shows various nozzle shapes. The generatrix shown at 5 has an inflexion, the shape shown at 4 reduces the maximum stresses in the material is lower. 展开 收藏 引用 批量引用 报错 分享 ...
and the "sequence" of a gene—its structural pattern— determines the kind of protein it makes. Some proteins become building blocks for structural parts of the cell. Other proteins become molecular "machines" enzymes, hormones, antibodies that carry out the myriad activities necessary to keep the...
The intramolecular H-bond to either O3 or O4 leads to such a symmetrical energy barrier for ϕ1. Those interactions were found in the crystal structure of CDHB, as described below. However, the rotation along the ϕ3 coordinate is much more restrained. The barrier between the K1 and K...
Many different molecular shapes and forms have been used for the construction of the described structures. We have focused on nanostructures assembled using weak noncovalent interactions; it is note worthy, however, to see that some of the proposed structures are stable in polar solvents, such as ...