题目

--Do you like music that you can        ? --Yes, I do． A．sing along with                               B．sing along C．to sing along with                             D．sing along with it 答案：A某人做了一个实验，取甲、乙两支试管，分别加入新鲜血液后，甲试管内加入柠檬酸钠，静置一段时间后得到上层清液；乙试管中什么药品也没加，静置一段时间后，同样得到上层清液。甲、乙试管内的上层清液分别是A．甲是血浆、乙是血清B．甲是血清、乙是血浆C．两种都是血浆D．两种部是血清