题目

阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项。 A talented actor, producer, and singer, Will Smith is a success. In fact, his huge success can1back to some valuable lessons life taught him early on. Once Will's father2him an outdoor project. He had to rebuild a long 3wall in the yard. He had to4concrete and place one brick at a time, eventually covering the entire wall. Will felt surprised at their father's demand5 he couldn't even think of completing a project as big as this. However, with the 6of one brick mor给严重贫血患者输血，最有效最经济的是输入  A．全血 B．浓缩的红细胞悬液 C．浓缩的血小板悬液 D．血浆