下列哪种靶向制剂属于被动靶向制剂（）
A.热敏脂质体
B.长循环脂质体
C.免疫脂质体
D.脂质体
E.pH敏感脂质体
参考答案：D
We had to be patient because it ______ some time ______ we got the full results.
A．was; since
B．had been; since
C．was; before
D．would be; before
害虫
