When you are __ trouble,why not call the___?1.at,police 2.on,policeman 3.in,police 4.at,policeman

When you are in trouble,you can __ your parents __ help.空格填什么,为什么要用这个 What will you do when you are __ (孤独）at home? love will not end for marriage.when u are in true love ,u will forget your own trou ble and jiy,bulove will not end for marriage.when u are in true love ,u will forget your own trou ble and jiy,but care that of your partner. when __ you have a school trip中用do还是用are,理由? When the teacher are doing an experiment,you should __ (观察)it carefully. what should we do when we are on a bus?You should__ __ __ when you gei on the bus.怎么填? 当你学一门外语时你也在学一种新的文化 When you are learning a ___ ___ ,you are also learning a __ __ when you are gone when are you going? When are you going When are you going? swim when you are when are you when you are when are you when you are When are you ____London____Party. when you are gone