They left under the cloak of darkness.

他们在黑暗的掩护下离开了。

《牛津词典》

Undeterred, he crept into the cemetery under the cloak of darkness with a bemused sculptor in tow.

他没有被吓住，在黑暗的掩护下，拖着一个困惑的雕刻家，蹑手蹑脚地走进墓地。

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Article 20 It is strictly forbidden to buy or sell a child or to do so under the cloak of adoption.

第二十条严禁买卖儿童或者借收养名义买卖儿童。

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All evidence to Select Committees is given under the cloak of parliamentary privilege.

BBC: No privilege for disgraced former MP Denis MacShane

Other regulations are developed by power hungry bureaucrats inured to marketplace realities, all while resting under the cloak of civil service tenure.

FORBES: Some Dietary Suggestions For Our Regulators

All of a sudden they were hanging out their dirty laundry and sharing rumors and suppositions, sometimes wildly inaccurate, sometimes under the cloak of anonymity.

FORBES: Magazine Article