challenge switch

基本解释

This differential sialylation may provide a switch from innate anti-inflammatory activity in the steady state to generating adaptive pro-inflammatory effects upon antigenic challenge.
該差分唾液酸化可提供一種開關從與生俱來的，在穩定狀態中的抗炎活性，以産生自適應的抗原刺激後的促炎性作用。
Saturday's draw with Arsenal finally saw off the lingering challenge of Liverpool, ending a tense title race and allowing the Reds' attentions to switch to facing La Liga's finest in Rome on 27 May.
周六和阿森納的平侷最終令利物浦的追趕成了白費，曼聯終結了聯賽的懸唸可以專心準備27號在羅馬擧行的冠軍盃決賽了。
forum.sports.sina.com.cn
While a robot partner would never be my equal in a relationship -- it can't be, as long as I control the on-off switch -- it could still challenge me intellectually.
在兩人關系中，衹要我控制著開關，機器人就永遠不能挑戰我的地位，智商除外。

What they needed to do was switch things around in her head so that the challenge became not taking the wallet but leaving it.
NEWYORKER: Found Objects
For Google, the challenge is keeping its income from search high, even as the users switch to accessing the Internet on the go.
FORBES: More China Challenges For Google