Read the following paragraph and underline the topic sentence.Since 1975, the number of working mothers has risen by 1.2 million. Yet, 40 years later, women are struggling with work-life balance more than ever. There are many reasons for the increased struggle to keep all the balls in the air. One big reason is a greater responsibility for young female professionals moving into leadership roles. Some reasons are economic in nature. Slow wage increases and rising living costs often leave workers with no choice but to put in extra hours, sacrificing on the home front. In addition, there is often a conflict between women employees’ need for flexible time and employers’ unwillingness to give it. Some of the negative consequences for having a flexible schedule include being given a less significant position or even losing a job.