【单选题】
（）, we continued lifting out the pistons.
A、Late as it was
B、As it was late
C、Since it was late
D、Because of its late
查看正确答案
A、A.使LiF充分干燥 B、B.使LiF保持较好的形状 C、C.使LiF具有良好的硬度 D、D.使LiF保持良好的剂量响应和一致性 E、E.使LiF具有较高的发光效率
