The membrane activity most nearly opposite to exocytosis is:

endocytosis

Explanation:

Endocytosis is defined as the process of trapping a particle or even a substance from the external environment by the process of engulfing it. The flexibility of the cell membrane helps the cell to engulf the food and also other materials from the external environment. Such a process is called endocytosis whereas exocytosis is the fusion of secretory vesicles with the plasma membrane and results in the discharge of vesicle content into the extracellular space

there's the proffessional site that will you.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]