根据句意，写出括号内所给单词的适当形式。
We love our children and our parents love ______(they).
If giant pandas are in ______(dangerous), they will attack people.
______(luck), he was not badly hurt in the car accident last month.
Thousands of ______ (tour) come to the Great Wall every year.
The places ______(mark) in red are very dangerous.