题干
Could you speak in a __________ voice? We can hardly hear you.
A：friendlier
B：louder
C：softer
D：lovelier
答案(点此获取答案解析）
B
Could you speak in a __________ voice? We can hardly hear you.
A：friendlier
B：louder
C：softer
D：lovelier
匀加速行驶时牵引力为
，达到额定功率后最终以速度
匀速行驶。若汽车质量减半，牵引力为
匀加速行驶时加速度为
，达到额定功率后最终以速度
匀速行驶，则可以确定： （ ）