Ⅰ. 根据提示写出正确单词 1. The police said the accident ________ (发生) at about 4: 30 pm. 2. He _______ (抓住) my hand and shook it warmly. 3. This is the most important _______ (改革) of the police service in over 30 years. 4. We are so ________ for all the support we received. (thank)

occurred

grasped

reform

thankful