用沸程60-90度的石油醚提取水样中的有机氯农药,浓缩时水浴温度要控制在70-100度。
参考答案:对
—Look. What a nice garden!
—Yes, it _____ every day. [ ]
A. cleans
B. was cleaned
C. is cleaned
D. has been cleaned
男,61岁,患有高血压,同时伴有2型糖尿病,尿蛋白(+)。选择最佳降压药物为()
A.利尿剂
B.钙拮抗剂
C.ACEI
D.α受体阻滞剂
E.β受体阻滞剂