A spy operates secretly, in other words, by obtaining information on a secret basis.
A spy operates secretly, in other words, by obtaining information on a secret basis.
间谍的活动是秘密地开展的，也就是说，通过秘密的方式获取情报。
A spy operates secretly, in other words, by obtaining information on a secret basis.
间谍的活动是秘密地开展的，也就是说，通过秘密的方式获取情报。