用方框中所给词或词组的适当形式填空

prepare     on average   experience   challenge     earn

Climbing Mount Qomolangma is a        task for all people.
Many of today's travellers are looking for an unusual     .
I am       to travel to China with my parents next summer.
There are 20 people here every day     .
She gave all her       to her parents to support her brother to go to school.