正确答案1 It is our trouble that so far we haven’t worked out the right solution to our problem.2 Led by a villager, we had no difficulty finding his home.3 The medical team is made up of three doctors and two nurses.4 He was knocked down by a passing car while he was riding a bicycle5 As science and technology develops / With the development of science and technology, knowledge has become increasingly important9 The two brothers are different in interest / hobby7 Before taking action, we must take into account the possible consequences that there might be.8 We look forward to seeing / meeting you again.6 He finds it hard to get along with his fellow students10 With so much work waiting to be done, he has no time for a rest11 Carelessness cost him his future12 It was quite a few minutes before I realized what had happened / Quite a few minutes had passed before I realized what had happened 13 During the American Civil War, many black people rose against their cruel slave-owners.14 You had better not stop him, for he is quite bad-tempered and hardly ever listens to others15 After his death, his wife took over the business16 In memory of his deceased wife, he set up this charity foundation 17 We arrived at Shanghai Airport and got aboard our plane to Beijing18 Needless to say , this year it must be the coldest in many years19 This work is much more difficult than we expected.