Jessica is 34 years old and has just broken up with her boyfriend. She is depressed because her plan to have children by 35 will not happen. Jessica's internalized timetable telling her where she should be at a certain time in life is her:.

Social Clock

Explanation:

Social clock is the timetable that is issued by the society of culture for any certain event to take place at that proper and particular time.Events like marriage, job,study, retirement etc is set-up by social structure to be followed by people of society at certain age.

According to the question,Jessica is trying to keep up with her social clock as she is following personal timetable for reaching certain stages in life such as marriage,having kids etc. She will not be able to have kids at age of 35 as she had a breakup thus, she isn't able to work as per social clock.  

i think its toxic gasses but i could be wrong