在完全竞争的市场中,行业的长期供给曲线取决于 ( )
A.SAC曲线最低点的轨迹
B.SMC曲线最低点的轨迹
C.LAC曲线最低点的轨迹
D.LMC曲线最低点的轨迹
参考答案:C
The Russian rocket designer has died. For many years, he ______ as an important assistant to the father of Soviet space program.
A.serves
B.was serving
C.served
D.has served
某有机物的结构是:关于它的性质的描述正确的是[ ]
①能发生加成反应; ②能溶解于NaOH溶液中; ③能水解生成两种酸;
④不能使溴水褪色; ⑤能发生酯化反应; ⑥有酸性
A.①②③
B.②③⑤
C.仅⑥
D.全部正确