The secrecy policy causes search engine technology to remain largely a black art and to be advertising oriented.
保密政策使得搜索引擎技术在一定程度上保留着它神秘的面纱，并且面向广告。
2
Rather, each large eye is a dome-shaped bundle of tubes.As you move about, only the tubes that are oriented toward you appear black, giving the illusion that you are being tracked.
He became the first black artist to be prominently featured on that young, rock-oriented channel when the success of Billie Jean and Beat It became so overwhelming it could not be ignored.