问题
选择题
（2011•广州）若a＜c＜0＜b，则abc与0的大小关系是（ ）
A．abc＜0
B．abc=0
C．abc＞0
D．无法确定
答案
答案：C
∵a＜c＜0＜b，
∴ac＞0（不等式两边乘以同一个负数c，不等号的方向改变），
∴abc＞0 （不等式两边乘以同一个正数，不等号的方向不变）．
故选C．
搜题请搜索小程序“爱下问搜题”
（2011•广州）若a＜c＜0＜b，则abc与0的大小关系是（ ）
A．abc＜0
B．abc=0
C．abc＞0
D．无法确定
答案：C
∵a＜c＜0＜b，
∴ac＞0（不等式两边乘以同一个负数c，不等号的方向改变），
∴abc＞0 （不等式两边乘以同一个正数，不等号的方向不变）．
故选C．
★Speak loud. When you are not confident, you can’t do well 小题4:you want to do. Try to speak loud enough so that people can hear you 小题5: . The high voice can help you become more confident. ★Play sports. Physical exercise makes you tired but strong. A strong body helps you be full 小题6: confidence. ★Encourage yourself. 小题7: down a list of things you did during the day to see how many things you have done well. Give yourself praise(表扬) for the good things you have 小题8: . ★Pick up a hobby.小题9: you like singing, sing as much as you can. In some ways, a 小题10: can make you excellent. And it will make you happy and confident. |