Solidgeometryhasenabledastronomerstocalculatethepositionsoftheheavenlybodiesrelativetooneanother.
A、ontopofComets are still regarded with awe by some people.
Cometsarestillregardedwithawebysomepeople.
Some sea urchins海胆 have venomous (toxin) spines
Somechildrendisplayanunquenchable难以抑制的curiosityabouteverynewthingtheyencounter.
Withlasersscientistscanprobemanyphysicalprocesses,suchascombustion,oncebeyondourken.视野
