海豚生在海里,但海豚不是鱼,那么下列论述正确的是()。
A.鱼不是生活在海里
B.生活在海里的不一定是鱼
C.不是海豚的动物是鱼
D.不是海豚的动物都不是鱼
参考答案:B
单根钢绞线的组装件试件及钢绞线母材力学性能试验用的试件,不包括夹持部位的受力长度不应小于()。
A.0.5m
B.0.7m
C.0.8m
D.1.0m
An analyst does research about total, marginal and average product curve of labor. As more labor is hired, which of the following curves initially increases and then decreases
A. The average product of labor curve, but not the total and marginal product of labor curve.B. The marginal product of labor curve, but not the total and average product of labor curve.C. Both the marginal product of labor and the average product of labor curve, but not the total product of labor curve.