题目

—Did you have any difficulty catching yesterday’s lecture? —No．The professor spoke very clearly to make his speech easy ____. A．understood          B．understand           C．understanding         D．to understand 答案：D做试卷的时候，先审题，认真思考，然后写答案。完成这些活动的神经中枢在（ ）A. 大脑皮层B. 小脑C. 脊髓D. 脑干