In order to perform the monitor function, language learners have to satisfy at least three conditions. One of the conditions is ______ to monitor his production.

A. enough speech



B. much information
C. sufficient material


D. sufficient time

（）不属于锅炉内部检验的内容。

A、膨胀情况的抽查

B、锅炉密封、绝热情况的抽查

C、水（介）质处理情况的抽查

D、锅炉安全管理制度及其执行情况的抽查