        .        .    .     .    .       .           .              .       .     .              .     .                .    .     .    .       .          ...  ［   ］                     .  .    .            .           ［   ］                        ....    .   .  .  .  .          ...                 .          ［  ］ .       ［  ］             .  .   .  .           ...    .    .  .     .    .         .......