锋利的石头扎进了我的脚跟。

The sharp stone dug into my ___heel.

长途徒步后，我的脚跟起了水泡。

After the long hike, I had a blister on my ___heel.

她在疼痛的脚跟处贴了创可贴。

She applied a plaster to her sore ___heel.