题目

 2cos45°﹣（﹣）﹣1﹣﹣（π﹣）0． 答案：解：2cos45°﹣（﹣）﹣1﹣﹣（π﹣）0， =2×﹣（﹣4）﹣2﹣1， =+4﹣2﹣1， =3﹣．—She sings very ______. She wants to join you. —Sounds ______.A. well; good B. well; well C. good; well