When the plane is to take off has not been announced 飞机何时起飞还没有宣布为什么这边要使用 to take off又不能做谓语

has it been announced when the plane is to take off中为什么用when when Jack hears that--is coming soon,he goes to board the plane ... when is the plane to zhengzhou as soon as possible.怎么翻译? when is the next plane for America America前面为什么用介词for而不是to? the plane when we got to the airport When the plane is to take off has not been announced 飞机何时起飞还没有宣布飞机何时起飞还没有:When the plane is to take off has not 为什么这边需要用过去分词加announced 这是什么形式.? When a bird flew to the plane,it lost c_____ ____ is the most expensive way to travel ---by plane .A.how B.when C.what D.where It is known to all that light travels in straight lines.When the plane is to take off has not been announced . 是什么从句及句子成分 The plane hasn't arrived yet.Could you tell me________?A.why the plane is late B.how is the plane lateC.when will the plane arrive D.that the plane arrives When the plane is to take off has not been announced 飞机何时起飞还没有宣布为什么这边要使用 to take off又不能做谓语 London,the,to ,is ,plane,flying连词成句 The plane is going to leave Shanghai this afternoon.疑问句 The plane is going to leave Tianjin ____ The train is s_.I would like to take plane the plane is about to take ____in 5 minutes The plane ___ when we got to the airport A.had taken off B.was taken off C.is taking of选哪个 为什么 Can you tell me when the plane ( ) to America tomorrow?四个选项是：A.would fly B.has flown C.had flown D.is flying