Preparation of calcium citrate from eggshells by ultrasonic method .

超声波法制备蛋壳柠檬酸钙的工艺研究。

As a bush-era appointee , cohen had been walking on eggshells .

科恩作为布什时代任命的官员，他一直在如履薄冰。

Miss liu : yes , they are made of eggshells .

刘小姐，它们是真鸡蛋做的吗?

We never had to walk on eggshells around her .

我们从不需要在她周围小心翼翼。

Eggshells are created when this happens many times over within a short period of time .

当这一过程在短时间内多次重复之后，蛋壳就形成了。