例句與造句

1. Trilobites are rarer than in previous periods, on a steady trend towards extinction, represented only by the proetid group.
2. ""'Cummingella " "'is a genus of proetid trilobite in the family Phillipsiidae that lived during from the earliest Carboniferous until the last species'extinction in the Middle Permian.
3. ""'Triroetus " "'is a genus of proetid trilobite found in Upper Carboniferous-aged marine strata in Russia, and Lower Permian-aged strata of Thailand, Malaysia, Spitzbergen, Yukon Territory, and Middle Permian-aged marine strata of Oman and Texas.
4. It's difficult to find proetid in a sentence. 用proetid造句挺難的