4 sentences for 严肃 (yán​sù — strictly enforce)

1. 必须严肃处理违反校规的行为。

   bì​xū yán​sù chǔ​lǐ wéi​fǎn xiào​guī de xíng​wéi.

   Violations of school rules must be dealt with seriously.

   Source: Dong Chinese Dictionary

2. 对于这种违规行为，必须严肃处理。

   duì​yú zhè zhǒng wéi​guī xíng​wéi, bì​xū yán​sù chǔ​lǐ.

   Such violations must be dealt with severely.

   Source: Dong Chinese Dictionary

3. 学生在考试中作弊会被严肃处理。

   xué​sheng zài kǎo​shì zhōng zuò​bì huì bèi yán​sù chǔ​lǐ.

   Students caught cheating in exams will be dealt with severely.

   Source: Dong Chinese Dictionary

4. 由于违反了公司规定，他受到了严肃处置。

   yóu​yú wéi​fǎn le gōng​sī guī​dìng, tā shòu​dào le yán​sù chǔ​zhì.

   He was severely disciplined for violating company regulations.

   Source: Dong Chinese Dictionary