Thorpe next set out to determine exactly when the chaffinch learns to sing.接着,索普就开始研究苍头燕雀是在什么时候学唱歌的.The chaffinch has three or four songs and produces them in a specific order.苍头燕雀合唱三、四种歌,唱的时候按着一定的先后次序....
伦尼放缓车速，听到自行车轮胎在湿漉漉的路面上发出嘶嘶的响声。The tires of Lenny's bike hissed over the wet pavement as he slowed down.一阵嘶嘶的声音说明氧气正在放出.A steady hiss denoted that the oxygen was on.蒸汽漏出来时发出嘶嘶的声音.The steam escaped with a hissing soun...
Many school buildings are unsafe, and some are falling apart.许多校舍不安全，有些简直是摇摇欲坠。Dangerous undertows make swimming unsafe along most of the coastline.由于存在着危险的下层逆流，在大部分海岸线附近游泳都不安全。Critics claim the trucks are unsafe.批评家声称这些...