Complete each sentence with the correct form of the word given in brackets.
1. As teachers, we need to take (responsible)_ for looking after our students' health.
2. They had worked hard to earn more money in order to give their daughter a good (educate)_.
3. I knew it was a difficult (decide)_, but I have already made up my mind.
4. Mr. Brown is a nice person, but he's not much of a(n) (think)_.
5. I don't know to say it in French as I have only a limited (understand)_.
6. His parents died when he was three, so he had a(n) (happy)_ childhood.