—How often do you drop your English teacher a line? — ,but usually once a week.
73. The general asked his men to push _____ so they might overtake the retreating(败退的) enemy troop.
72. At the beginning, I had some difficulty with my English, and my teacher pulled me ______.
71. Such a small man can’t _____ reach the balloon one metre higher than he.
70. These books are _____ written for those who learn how to use computer. It’s an ABC of computer learning.
69. In order to keep fit, the retired women, whether rain or shine, go _____ for plenty of exercise early in the morning.