Teeth covered by an operculum can be difficult to clean with a toothbrush.

被盲袋覆盖的牙齿很难用牙刷清理。

The contact between the operculum and the shell appears to be uneven but not indented.

卵盖与卵壳连接处虽不很整齐，但并不呈锯齿状。

Cells in the right parietal operculum operate as we act in response to other's gestures.

当我们对他人的手势作出反应时，起作用的是我们右顶骨的细胞。

Micropylar collar, operculum and parenchyma cells are differentiated at micropylar region.

种子珠孔区分化出珠孔领、孔盖和珠孔区薄壁细胞。