用恰当的疑问词填空。

1. —______ do you go to school?

    —I go to school at 8:00 every day.

2. —______ does your uncle live?

    —He lives in Shanghai.

3. —______ do you spell your name?

   —M-A-R-I-A, Maria.

4. —______ is the post office?

   —It's over there.

5. —______ do you like bananas?

    —Because they're delicious.

WG-21A型无绝缘轨道电路在调整状态下，轨道电路接收器限入电压应不小于（）mV，轨道继电器电压应不小于（）V，并可靠工作。