命题甲,命题乙:x2=y2(x,y∈R)甲是乙的()
A. 充分但非必要条件
B. 必要但非充分条件
C. 充要条件
D. 即非充分又非必要条件
Last night, a fire broke out in Ann&39; s house in Manchester.
Ann&39; s ——21 were out of town for the weekend when something wrong in the room caused the fire to start in the middle of the night. The ——22 was waken up by the family dog, Danny, who was barking loudly in the back garden. Ann smelled something ——23 . She ——24 and ——25 ran through the smoke-filled house to wake her old brother, Frank.
When Frank would not wake up, Ann got some help from the dog. Frank&39; s unconscious body was far too ——26 for the little girl to move alone, but the ——27 girl brought the dog ——28 and tied the dog&39; s lend to Frank&39; s left ankle. She then held her brother’s right ankle, and together the girl and the dog ——29 Frank to safety. The 10 year-old girl, Ann, ——30 her big brother from death.
21. A. parents B. brother and sister C. friends D. classmates
22. A. child B. boy C. girl D. dog
23. A. delicious B. bad C. burn D. burning
24. A. stand up B. wake up C. get up D. put up
25. A. at once B. at first C. at last D. at the moment
26. A. big B. small C. light D. heavy
27. A. careless B. busy C. clever D. careful
28. A. inside B. outside C. back D. near
29. A. pushed B. pulled C. carded D. made
30. A. was received B. get C. was saved D. saved