【名词&注释】
体外受精(in vitro fertilization)、同源人工授精(artificial insemination by husband)、异源人工授精(artificial insemination by donor)、无性生殖(asexual reproduction)、适用于(suitable for)、延伸度(extensibility)
[单选题]属于咀嚼黏膜的是
A. 唇黏膜
B. 颊黏膜
C. 软腭黏膜
D. 硬腭黏膜
E. 口底黏膜