firm ground

基本解释

You must always build on firm ground.
你必须始终脚踏实地。
He alone has stretched out the heavens and walks on the sea as on firm ground.
他独立拉出了诸天，并在海上漫步，恰如在坚实的陆地上一般。
foxue.org
Foreign companies operating in China must also make business deals on the firm ground of reliable commitments, excellent quality, and mutual trust.
在中国的外资企业也应该把商业活动建立在可靠的承诺、卓越的质量和相互信任这个坚实的基础上。

But defenders of the idea are on firm ground when they say that the practical objections to national service are wrong.
ECONOMIST: Lexington
Instead of falling off the abyss, it is on firm ground.
WHITEHOUSE: Press Briefing with Vice President Biden and Press Secretary Gibbs The White House