— Is Lucy still hunting for a job?

— Yes. She _________ for 7 months. [    ]

A. isn't employed  

B. wasn't employed

C. isn't being employed      

D. hasn't been employed

在西门子S7系列PLC规定的基本数据类型中，浮点数的位数是（）。

A、8

B、16

C、32

D、64