In the sentence “My life’s work is built around the belief that being connected makes our lives richer and more rewarding (Para. 6, L2-3)”, “being connected makes our lives richer and more rewarding” is used to explain the abstract noun “belief”. “that” here is used to introduce an appositive clause rather than an attributive clause (that这里引导的是一个同位语从句而非定语从句).

A. 对
B. 错