衡量材料抵抗变形能力的指标是（）；衡量材料轻质高强性能的指标（）是（）。
参考答案：弹性模量；比强度
It's hard to get _____ work these days. It is said, however, that he has been offered _____ nice job in a
big company.[ ]
A. a; a
B. /; /
C. /; a
D. a; /
婴儿饮食中，三大营养素(蛋白质：脂肪：碳水化合物)所供热量的百分比正确的是
A．25:40:35B．25:35:40C．15:50:35D．25:25:50E．15:35:50
