Brenda sent her son to the park to play basketball with his friends. ( ), she got dinner ready for the family. When her son came home, they ate dinner together.
Meanwhile
Professor Holt was surprised by his students' ( ) of World War Ⅰ. Because they knew so little, ( ) he decided to spend more time on the topic.
ignorance
The salesman decided to increase the ( ) of his visits to his main clients. In the past, he only visited them once a month, but now he goes every week.
frequency