TheeconomyofDallas,Texas,isstronganddiversified.
A、inflatedComets are still regarded with awe by some people.
Solid geometry has enabled astronomers to calculate the positions of the heavenly bodies relative to one another.
Insectpestsareamongtheleadingcausesofcropfailure.
Blue－greenalgaegrowabundantlyinsaltmarshes.
Eyespots,themostrudimentaryeyes,arefoundinprotozoan原生动物flagellates鞭毛虫,flatworms扁形虫,andsegmentedworms片段蠕虫.
