按要求填空。     

1．你知道下列称谓指的是怎样的朋友吗？

     布衣之交：                                                                                              

     忘年之交：                                                                                              

     贫贱之交：                                                                                              

2．“岁寒三友”是指                                                                                                

3．“花中四君子”是指                                                                                              

管道施工工程试压时所选压力表精度不应低于（）。

A、0.4级

B、0.6级

C、1.0级

D、1.5级