He believes that as far back as 30,000 B.C., hunters may have used a system of notation, engraved on bone and stone, to mark phases of the Moon.

他认为，远在公元前30,000年以前，猎人可能会用一套刻在骨头和石头上的符号系统来标记月相。

youdao

The Achilles tendon is a strong fibrous cord that connects the muscles in the back of your calf to your heel bone.

阿基里斯腱是将小腿后部的肌群连接到跟骨的强健的纤维索。

youdao

Achilles tendinitis is inflammation of the Achilles (uh-KIL-eez) tendon, the band of tissue that connects calf muscles at the back of the lower leg to your heel bone.

阿基里斯腱炎(译者：跟腱炎)是阿基里斯腱发生的炎症反应，阿基里斯腱是指将小腿后部的腓肠肌连接到跟骨上的一条组织。

youdao

Economist Vincent Chan from Credit Suisse in Hong Kong believes the main problem for the government is to manage expectations of the second generation of migrant workers who form the back bone of China's success.

VOA: standard.2010.06.24

Under new manager Paulo Sousa, Williams has continued to form the back-bone of Swansea's defence this season and also has two goals.

BBC: Williams takes top Welsh awards

"We believe, as a party, that education in Belfast has been cut back to the bone, " he said.

BBC: NEWS | UK | Northern Ireland | Board cuts lead to resignations

According to the minister, the back bone of the government's strategy in terms of delivery will be through the new Family First programme complimented by existing projects such as Flying Start.

BBC: Children and Young People Committee