免疫活性细胞是指()
A．参与免疫过程的所有细胞
B．巨噬细胞
C．B细胞
D．T细胞
E．B、T细胞
参考答案：E
He said the flowers wanted _____ but in fact he wanted _____ to play. [ ]
A. watering; going
B. to water ; to go
C. watering ; to go
D. to water ; going
在工具显微镜上，用轴切法测量可提高（）精度。
