88. Dennis is very dangerous. He can ______________ (喷火).

87. The girl ___________________ (从 ……出来) the teachers' office, smiling.

86. If you___________ (感到不舒服), you'd better see a doctor.

85. Don't ___________(放弃)! Keep on ___________ (努力)!

84. ______________ (赶快) or you'll be late for the meeting.

83. We ___________ (吃惊) to hear that Miss Wang ____________________ (病得很厉害).

82. Tom _________ (离开) from school for a month, so now he's got to work hard ____ (赶上) the rest of class.

81. In autumn leaves turn yellow and then ______________ (掉到地上).

80. Please ______________ (上) the bus quickly!

79. I _____________________ (吃了一惊) yesterday. I __________ (收到) a letter from America.