For the better part of a century, most biologists have been reluctant to use those words, mindful of a principle of evolution that says "evolution cannot run backwards".(在大半个世纪里，大多数生物学家都不愿使用这些词，因为他们牢记着一条进化论的原则，即“进化不能倒退”。)
I lost my balance and fell backwards.(我没有站稳，仰面摔倒。)
In medieval times, a lance couched under the rider's arm, unifying the force of rider and weapon, would throw its wielder backwards off the horse at impact.(在中世纪，一把长矛被放在骑手的臂膀下，以统一骑手和武器的力量，一旦受到冲击，持兵器者就会向后摔下马去。)
There was a heart-stopping moment when she lost her balance and fell backwards.(她失去平衡向后倒的那一刻着实令人心悸。)
The third wave was so strong it knocked me backwards.(第3个浪头如此猛烈，把我击得往后退。)
He gave her a hard push which toppled her backwards into an armchair.(他给了她用力的一推，将她向后推倒在一把扶手椅上。)
We destroy it through the backwards process.(我们通过逆向过程来破坏它。)
The asocial robot simply moved forwards and backwards and side to side.(社交机器人只是向前、向后、左右移动。)
He took a step backwards.(他退后一步。)
'Ambulance' is written backwards so you can read it in the mirror.(ambulance是倒着写的，以便在镜中认读。)
