40. You can’t see the president ______ you’ve made an appointment with him. (A)if (B)unless (C)when (D)except

45. What is the main idea of the last paragraph? (A)There is nothing wrong with teenagers admiring pop singers and sport stars. (B)Pop singers and sport stars should not be heroes of our children. (C)If our children admire pop singers and sports stars, it is the parents who are to blame. (D)Parents should set a good example for their children to follow.