It is reported that air pollution affects rivers and lakes indirectly because it causes acid rain.

It is the responsibility of the Master or person in charge of a ship to ensure that（）.

It is the responsibility of the Master or person in charge of a ship to ensure that（）.

It should be apparent that little or nothing is gained by opening a drain at the same time as or after admitting steamThe above sentence probably means （）.

大学英语等级考试是一种（ ）测验。

Project（71）is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

Project ______is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

● Project（71）is an uncertain event or condition that, if it occurs, has a positive or a negative effect on at least one project objective, such as time, cost, scope, or quality.（71）

 ______ twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.

某大学为了了解学生的英语掌握情况，就调查了外语学院大二年纪两个班的学生，这些学生英语四级通过率为75％，因此得出结论：该校学生英语能力为良好，这个结论是合理的。

Whilst the engine is turning, check to see that no water is leaking into the crankcase, scavenge air belt, or from （）.

（）generally indicates that a gale or storm is approaching.