题目

The guide said that much attention must ______ these details.      A. pay         B. be paid         C. pay to            D. be paid to 答案：D如图，MN是半径为2的⊙O的直径，点A在⊙O上，∠AMN=30°，点B为劣弧AN的中点．点P是直径MN上一动点，则PA+PB的最小值为（ ）．A．1 B． C．2 D．2