What is a precipitin test? what is it used for?

Vertebrates have this type of circulatory system: wut i it owo

In the city of newark, a young man named annoying was admitted to the e.r. he and his friends were trying to imitate the movie project x. his friends say he started twitching and having muscle spasms which progressed until he was stiff as a board. in his pockets, he had unmarked dark yellow tablets which dark flecks. analysis of the tablets showed them to contain a mixture of ecstasy and strychnine. ecstasy would not cause this clinical picture, but strychnine would. explain why?

At what age does trust usually begin to develop? a. 25 weeks b. 20 weeks c. 15 weeks d. 10 weeks