Thirteen new compounds of the alkyl styryl indoline spirobenzopyrans were synthesized from the condensation of 2-methylene indoline with the designed salicylaldehyde.
Approximately thirteen seconds before impact, the Copperhead's laser light sensor becomes active, and it uses fins to guide itself to the laser light source.
In chapter thirteen, Aristotle outlines an ideal of the central character of tragedy, the so-called tragic hero, and identifies the source of the character's downfall with something called hamartia.
（汇总） 
5月合集 
英国皇家空军度过了13年。
认为十三是个不
利的数字。
。
月， 而立法运动举步维艰。
以来，已经有13场比赛中的获胜马赢得了三冠王。
