那只猫从敞开的窗户悄悄爬了进来。

The cat ___crept in through the open window.

她沿着走廊悄悄移动，以免吵醒任何人。

She ___crept along the corridor so as not to wake anyone.

在黑暗的掩护下，间谍悄悄溜出了敌人的营地。

Under cover of darkness, the spy ___crept out of the enemy compound.