5. Explain some important points
(1) call up : ring up打电话,使…回忆起
call back召唤某人回来;再访;回电话  
call for  需要,要求,接(人或物)
call in   邀请;请来
call on   拜访(人);
call at  拜访(某地)
call off  取消
Ask Ss to use the above phrases to fill in the following blanks:
① Let’s go to the meeting together ,and I’ll ______you.
A. call on    B. call at   C. call up     D. call for
② The football match was ________ on account of the weather.
   A. call back   B. call off   C. call in     D. call for