【名词&注释】
支气管(bronchial)、体外受精(in vitro fertilization)、淋巴结(lymph node)、腔隙性脑梗死(lacunar infarction)、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)
[单选题]腔隙性脑梗死的大小一般是( )
A. 小于2mm
B. 2~15mm
C. 15~20mm
D. 20~25mm
E. 大于25mm