Next, the cancer can invade nearby tissues like the pectoral muscles below and the skin above.

其次，癌症可以侵袭附近组织，如其和其上皮肤。

They lie on top of the ribs and the pectoral muscles, and they're divided into three main parts.

他们位于肋骨和方，可以被分为三个部分。

The breast becomes immobile and fixed, or stuck onto the chest wall due to infiltration if cancer cells spread into the pectoral muscles.

如果癌症累及，会变得难以推动，粘于壁上。

To flap their wings at this speed, hummingbirds have evolved giant pectoral muscles that comprise over a third of some species' bodyweight.

为了以这种速度拍打翅膀，蜂鸟进化出了巨大，其占某些物种体重三分之一以上。