Today's tests still work by measuring HCG. But, throughout the 20th century, other methods were explored; the AZ Pregnancy Reaction Test popped up in 1928 and was the first of several " bioassays" or animal-based tests.

今天的测试仍测量人绒毛膜促性腺激素来工作。 但在整个20世纪，人们探索了其他方法；AZ怀孕反应测试在1928年出现， 是多个“生物测定” 或基于动物的测试中的第个。

The last fossils of Condors in the Grand Canyon, for example, have been dated to around 10,000 years ago, which is very soon after most megafauna, like that mountain goat, went extinct in the area.

例如，大峡谷中最后的神鹫化石被测定为大约万年前，这紧随大多数巨型动物，比如那种山羊，在该地区灭绝之后不久。

From Scotland: A geologic-dating effort suggests the fossil of a millipedelike creature found on the island of Kerrera formed 425 million years ago, making it possibly the oldest-known fossilized land animal.

来自苏格兰：项地质年代测定工作表明，在凯雷拉岛上发现的种类似千足虫的生物化石形成于4.25亿年前，这可能使其成为已知最古老的陆生动物化石。