Roberta married for the first time at age 39, and at age 40 she is pregnant for the first time. she is now considering starting college to become a computer systems engineer. when roberta laughingly tells her friends, "i have never done anything when i was supposed to! " what is she referring to?

Social clock

Explanation:

Social clock is a social explicit timetable for occasions to happen. Occasions incorporate marriage, having kids, and so forth. For instance, in certain societies it is normal that individuals be hitched in their adolescents.  

It incorporate for all intents and purposes whatever individuals generally do for the duration of their lives.

industry had made the u.s. the richest nation in the world at this time. the second industrial revolution caused growth in industry and transportation, which allowed increased trade between nations.

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.