当x<0时,函数y=-2x的图象在( )
A.第一象限
B.第二象限
C.第三象限
D.第四象限
答案:B
When I went to say goodbye to Anna, she ________ the piano. [ ]
A. is playing
B. plays
C. was playing
D. played
关于伤寒杆菌抵抗力下列哪些是正确的()
A.在自然环境中生命力强,耐低温
B.水中可存活2~3周
C.粪便中可存活1~2个月
D.60℃,15分钟或煮沸后即可杀灭
E.对一般消毒剂不敏感