关于多巴胺和去甲肾上腺素的叙述，错误的是（）
A.都是儿茶酚胺类药物
B.都有心脏兴奋作用
C.都有升压作用
D.都有舒张肾血管的作用
E.都属于神经递质
参考答案：D
解析：多巴胺的突出特点是治疗量可激动多巴胺受体，血管舒张，尤其肾血管及肠系膜血管。但大剂量时可因兴奋肾血管上的α受体而致肾血管收缩，使肾血流减少，而去甲肾上腺素是α受体激动药无舒张肾血管的作用，所以D是错误的。
| In most cases, you can transplant a tree successfully, at any time, if you follow the instructions for planting a tree. The most important thing is to dig out enough roots, but this process is difficult with a large tree. When you dig out the tree, leave a ball of earth around its roots. This ball of earth should measure about a foot wide for every inch of the tree trunk’s diameter. Dig deep enough to avoid cutting off too many taproots. It is wise to call in a professional tree expert to transplant a tree more than a few inches in trunk diameter. |
The best time for transplanting a tree is ______.
A．spring
B．fall
C．winter
D．any season