The children were entrusted ___ the care of their uncle.

• Entrust: to give someone a thing or duty for which they are responsible.

• Entrust Subject with Something: (Task)
- Many people had entrusted the company with money they intended to use in retirement.
- Be entrusted with something/somebody: I was entrusted with the task of looking after the money.

• Entrust Something to Subject: (Person)
- He entrusted the arrangement of a mortgage to a local firm of financial advisers.
- Government has been entrusted with elected politicians.

• Entrust Subject to do Something: (Person)
- We entrust a board of Edinburgh's leading businessmen to run the affairs of the organization.

• উপরের উদাহরণগুলো বিশ্লেষণ করলে বুঝা যায়,
- somebody এর ক্ষেত্রে entrusted to হয় এবং something এর ক্ষেত্রে entrusted withe হয়।
- এখানে বাক্যটি Passive voice এ রয়েছে। তাইHe was entrusted to হবে।
- Complete Sentence: The children were entrusted to the care of their uncle.

Source: Cambridge Dictionary