The first important exposition in the United States was held in Philadelphia in 1876.

Alligators still exist in some of the dank 潮湿 swamps and bayous小海湾 of Alabama's coastal regions.

In the northeastern United States, it rains intermittently 间歇地 throughout the spring.

Alligatorsstillexistinsomeofthedank潮湿swampsandbayous小海湾ofAlabama'scoastalregions.

Eyespots,themostrudimentaryeyes,arefoundinprotozoan原生动物flagellates鞭毛虫,flatworms扁形虫,andsegmentedworms片段蠕虫.