【判断题】社会保障的特点有:经济保障、社会性、合法性、人道主义。()
【单选题】Section B Mini-talk one
C.
The University of Pennsylvania
【简答题】Directions: In this section, you'll hear a mini-talk. Listen carefully and then fill in the numbered blanks with the information you've got. Fill in each blank with NO MORE THAN 3 WORDS. You'll hear t...
【单选题】根据截平面相对圆锥的位置关系不同,圆锥的截交线形状总体共有( )种情况