Ⅰ. Fill in the blanks according to the given tips, using their proper form.
1. I was busy _____(look) for my umbrella.
2. My parents were completely _____(shock).
3. He has trouble in _____(learn) English.
4. You should tell us the _____(true).
5. Her mother _____(cook) at 6:30 yesterday.
6 . Robert walked home in _____(silent).