减小叶片进口变宽度，是防止泵发生气蚀的一种方法。
参考答案：错
解析：增大叶片进口变宽度，是防止泵发生气蚀的一种方法。
The figure above is a regular hexagon with center H, The shaded area is a parallelogram that shares three vertices with the hexagon; its fourth vertex is the center of the hexagon. If the length of one side of the hexagon is 8 centimeters, what is the area of the unshaded region ？（）
A.A
B.B
C.C
D.D
E.E
