The central portion, however, was more modern, and a curl of blue smoke escaped from the chimney.

然而，中央部分更加现代，烟囱里冒出一缕蓝色的烟雾。

The aorta also undergoes cystic medial necrosis, which is where there is degeneration of the tunica media, which is the central portion of the aortic wall.

除此之外，主动脉还会有囊性中层坏死，即主动脉的中膜发生退行性变；中膜是主动脉壁的中心部分。

The ground floor and the upper floor of that battered house are alike deserted, and the inmates keep the central portion, just as in a dying body all life retires to the heart.

那间破房子的底楼和楼上都空无一人， 居者居中，犹如垂死之躯， 所有生命都归于心。