2 sentences

1. 这项活动的参加次数没有限制。

   zhè xiàng huó​dòng de cān​jiā cì​shù méi​yǒu xiàn​zhì.

   There is no limit to the number of times you can participate in this activity.

   Source: Dong Chinese Dictionary

2. 一个二次方程的最高项次数是二。

   yī​gè èr​cì fāng​chéng de zuì gāo xiàng cì​shù shì èr.

   The highest degree of a quadratic equation is two.

   Source: Dong Chinese Dictionary