题目

The opening ceremony of the 11th National Games, ______ in Jinan, Shandong Province from Oct.15-28 was highly praised. A. to be held         B. being held                C. held                        D. having been held 答案：C 解析: 略不同动物激素的作用方式有一些共同特点。下列选项中，不属于动物激素作用特点的是（ ）A. 微量和高效 B. 通过体液运输C. 通过导管运输 D. 作用于靶器官、靶细胞