根据汉语提示完成下列句子。
1. We have to ____________ ___________ ___________(想出) some new ideas to solve the
environment problems.
2. The police found the lost car _____________ _______________(偶然地).
3. Watching the new TV play Yimeng _____________ ___________ ___________(使我想起)
my hometown.
4. I ___________ _____________ (有困难) in learning grammar and memorizing new words.
