They did not find ___ to prepare for the worst conditions they might meet. 

He volunteered to work in a remote mountainous village in West China last year, which is still _____ on foot now.

It is immediately obvious that water is to be _______ to the development of life.

The instructor asked us to list anything in our past that we felt ______ of，regretted and read our lists aloud.

 Mothers love children, which is a(n) _______fact in spite of cultural differences.