sustaining是什么意思？

However, Dr Mehmood Khan,chief scientific officer, said the company had doubled research and development spending in the past five years and was "committed to sustaining investment", adding that companies cannot cost-cut their way to increasing sales.

For almost five centuries a very large supply of cod provided abundant raw material for an industry which at its peak employed about 40,000 people, sustaining entire communities in Newfoundland.

Only a handful of islands in the Southern Ocean are suitable for sustaining large breeding colonies.