有关Tl／TcO显像减影法的描述错误的是（）

A.注射Tl74MBq

B.低能高分辨或低能通用平行孔准直器的γ照相机进行前位甲状腺部位显像

C.然后再静脉注射TcO185MBq

D.应用计算机图像处理软件将Tl甲状腺影像减去TcO甲状腺影像，即得到甲状旁腺影像

E.两种显像剂不能同时注射

About fifty years ago, plant physiologists set out to grow roots by themselves in solutions in laboratory flasks. The scientists found that the nutrition of isolated roots was quite simple. They required sugar and the usual minerals and vitamins. However, they did not require organic nitrogen compounds. These roots got along fine on mineral inorganic nitrogen. Roots are capable of making their own proteins and other organic compounds. These activities by roots require energy, of course. The process of respiration uses sugar to make the high energy compound ATP, which drives the biochemical reactions. Respiration also requires oxygen. Highly active roots require a good deal of oxygen.The study of isolated roots has provided an understanding of the relationship between shoots and roots in intact plants. The leaves of the shoots provide the roots with sugar and vitamins, and the roots provide the shoots with water and minerals. In addition, roots can provide the shoots with organic nitrogen compounds. This comes in handy for the growth of buds in the early spring when leaves are not yet functioning. Once leaves begin photosynthesizing, they produce protein, but only mature leaves can "export" protein to the rest of the plant in the form of amino acids.

Where is this passage likely to be found

A．A newsletter.

B．A magazine.

C．A storybook.

D．A novel.