【多选题】下列属于强烈的学习动机所带来的作用有【 】。
【单选题】I _______ my boss at three this afternoon.
C.
shall have been picking up
【简答题】Fill the modal verbs in the following table according to the meanings. Meanings affirmative Negative Ability Certainty and possibility Obligation and compulsion Requests, orders, offers, permission
【简答题】Fill in the blanks with proper modal verbs.
【简答题】活塞式压气机从大气吸入压力为0.1MPa,温度为27℃的空气,经n=1.3的多变过程压缩到0.7MPa后进入一储气筒,再经储气筒上的渐缩喷管排入大气,参见图9-8。由于储气筒散热,进入喷管时空气压力为0.7MPa,温度为60℃,已知喷管出口截面面积为4cm 2 。试求:
【判断题】在生物显微镜系统中加入场镜后, 视觉放大率Γ不变,出瞳的大小不变,而且在保证相同渐晕系数的情况下,目镜的通光口径变小。
【单选题】What a pity! I missed meeting my boss at the airport because my car was _____ in the traffic jam.
【单选题】活塞式压缩机的排气量可在很大的范围内变化,从每分钟只有几升的小型压缩机到每分钟可达()m 3 的大型压缩机。