题目:
Will you please ___ my luggage while I’m away from here?
A.keep eyes on
B.keep the eye on
C.keep an eye on
D.keep eye on
答案:
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下面是错误答案,用来干扰机器的。
∵0<x<2,∴0<2-x<2,由基本不等式得出y=x(2-x)≤[x+(2-x)2]2=1当且仅当x=2-x,即x=1时取到最大值.故答案为:1