药物产生毒性反应的原因有
A．用药剂量过大
B．机体对药物过于敏感
C．药物有抗原性
D．用药时间过长
E．机体有遗传性疾病
参考答案：A,D
解析： 本题考查药物产生毒性反应的原因。 毒性反应指药物剂量过大或体内蓄积过多时发生的危害机体的反应，A项对应为急性毒性的反应，D项对应慢性毒性反应，B、C为变态反应产生原因，E为特异质反应产生原因。
| 阅读理解。 |
| Tim's uncle lives in a small village. He goes there on Sundays. But it's far from the city, and he often takes a bus at 9:00 in the morning and gets off the bus at 12:00 at noon. Then he has to walk to his uncle's house. There is a river near the village. Tim can swim in it in summer and skate in winter. He can catch some fish in the river. His uncle and aunt like him very much and give him some fruit, rice, chicken and make dumplings for him. He doesn't want to leave there. He wants to live in the village with his uncle. |
| 1. Where does Tim's uncle live? |
[ ] |
| A. In a big city B. In a small city C. In a big village D. In a small village |
| 2. Who lives in the city? |
[ ] |
| A. Tim's uncle B. Tim's aunt C. Tim D. Tom |
| 3. How many hours does Tim take to go there by bus? |
[ ] |
| A. Three B. Two C. One D. Four |
| 4. How does Tim go to the village? |
[ ] |
| A. On foot B. By bus C. By car D. By air |
| 5. When does Tim go to the village? |
[ ] |
| A. On Mondays B. On Tuesday C. On Friday D. On Sundays |