2 sentences for 入学 (rù​xué — start school)

1. 在很多国家，六岁是法定的入学年龄。

   zài hěn​duō guó​jiā, liù suì shì fǎ​dìng de rù​xué nián​líng.

   In many countries, six is the legal age for starting school.

   Source: Dong Chinese Dictionary

2. 所有适龄儿童都必须入学接受义务教育。

   suǒ​yǒu shì​líng ér​tóng dōu bì​xū rù​xué jiē​shòu yì​wù jiào​yù.

   All school-age children must be enrolled in compulsory education.

   Source: Dong Chinese Dictionary