Here is the passage with the words and phrases filled in:
Bobby's parents decided to send him to playschool when he was three. They wanted him to learn to play with other children. In Britain, children must, by law, start school at the age of five. Education is compulsory from then. Bobby's first real school was a primary school. There are three terms a year and holidays at Christmas, Easter, and in summer. The pupils are boys and girls together, so it is a mixed school. The teachers of the state school are young and friendly. Bobby likes the school.
Sally has just started her new school at the age of 11. There are different kinds of school from this age, but the general term for them is secondary school. Sally's school is a government school, usually called a state school. Some parents pay to send their children to a private school.
At first, Sally will take a lot of different subjects (History, English, Chemistry, etc.), but, after a few years, she'll begin to specialise in things she is good at and interested in. Then she'll take some exams. If she can pass a number of exams with good marks (A, B, C), it will help her to get a good job. Of course, she hopes she doesn't fail.