Final answer:
Providing judicial review is how this acts as a check on Parliament in law-making.
Step-by-step explanation:
The act that acts as a check on Parliament in law-making is providing judicial review. Judicial review is a process in which the courts review the constitutionality of laws and actions taken by the legislative and executive branches of government. Through judicial review, the courts have the power to declare laws passed by Parliament as unconstitutional and nullify them, thereby limiting the power of Parliament in law-making.