尽管他做出了保证，但我对这个雄心勃勃的计划的可行性仍持保留意见。

Despite his assurances, I still have some ___reservations about the feasibility of this ambitious plan.

她同意帮忙，但并非没有对我们方法的道德影响表达了强烈的保留意见。

She agreed to help, but not without expressing strong ___reservations about the ethical implications of our approach.

他对所提议的政策变革根深蒂固的疑虑源于数十年的实践经验。

His deep-seated ___reservations about the proposed policy change were rooted in decades of practical experience.