四六级考试

【单选题】
A、They migrate from NorthAmerica to the Falkland Islands.
B．They migrate only once during their lifetime.
C．They migrate using what is apparently an inborn navigational ability.
D．They migrate when they are freed from their cages.

网考网参考答案：C
网考网解析：
How do warblers migrate according to the passage document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>