Use the verb in the Principle Clause in the Past Tense and make all the necessary changes:A-1.we know that we are going to begin our work tomorrow.2.I think it is beginning to rain.3.she says she is washing up and her sister is watching television.4.they say it is snowing heavily and a strong wind is blowing.5.he says they are going to Britain for summerholidays.B-1.i think they have returned from the trip.2.they say they have made and lot of pictures of New York.3.we know you have travelled all over America.4.she says she has made some interesting new friends.5.he is sorry he has not been able to pass the exam.6.i am sure they have received our letter.7.she does not remember how long they have been leaning English.8.she says it has been raining ever since morning.