两拉杆的材料和所受拉力相同，且均处在弹性范围内，若两杆长度相等，横截面面积A1>A2，则：（）
A.A
B.B
C.C
D.D
参考答案：C
解析：
—Oh, no ! There is no sugar left .
—_____. I’ll buy some when I go into town.
A ,Good idea B. Not at all C. Never mind
