A filled torus (a doughnut) is a 3-manifold homeomorphic to \(S^1 \times D^2\), where \(D^2\) is the 2-dimensional disk. There exists a deformation retract from the doughnut to a circle, so the fundamental group of the doughnut is \(\pi_1(S^1 \times D^2) \cong \mathbb{Z}\).
(一)组织、胁迫、诱骗不满十六周岁的人或者残疾人进行恐怖、残忍表演的;
。爱思助手下载最新版本对此有专业解读
Израиль нанес удар по Ирану09:28
�@���Ԓ��ɃL�����y�[���T�C�g�����G���g���[���A�͂����܂̑ΏۓX�܂�d�|�C���g�J�[�h���A���v50d�|�C���g�ȏ������߂����[�U�[���ΏہB���I�ňȉ��̒ʂ��Ad�|�C���g���t�^�����B