test (hence and therefore)

Hi,
I was confused about these two questions. You have "hence" and "therefore" to fill the blanks. I would appreciate it if you kindly answer my questions and give me points that would help me to answer similar questions in the future.

1. The young boy refused to obey the teacher. _____________, he was sent home.

2. The prime minister has already announced his intention to step down, and _____________ is no longer regarded as influential in directing future policy initiatives.

Thanks,