Tom always does some exercises in the morning.改否定句
问题描述:
Tom always does some exercises in the morning.改否定句
答
Tom always doesn't do any exercises in the morning.东西两地相距198千米,甲丙两人从东往西,乙从西往东,三人同时出发,甲的速度12千米(时),乙的速度10千米(时),丙的速度8千米(时)。乙与甲多少小时相遇?乙与甲相遇后几小时乙与丙相遇?198÷(12+10)=9小时乙和甲9小时相遇198÷(10+8)=11小时11-9=2小时乙与甲相遇后2小时乙与丙相遇。胖胖从家去少年宫,去时用了25分钟回来时多用了5分钟,两地路程相距550米,胖胖的平均速度是多少?550 ÷(25+25+5)=10m/s