管道安装前对管道内部可不进行清理，待安装完成后再进行整体清理。
参考答案：错
Which of the following sentences is NOT right?[ ]
A. There is no doubt that you will succeed.
B. We have no doubt that you will succeed.
C. We don't doubt that you will succeed.
D. We don't doubt whether you will succeed
电力生产设备火灾扑救后，必须（）火灾现场。
