公鸡竖起了鸡冠.The rooster bristled his crest.动物模型的选择为 猪肝 及鸡冠.The Nd: YAG laser illumination ranged from 20 to 60 W.而且像是鸡嘴, 鸡冠,还有一些羽毛都是清晰可见.The chicken's beak, the comb and some feathers were visible....
如果使用得当，避孕套是很有效的避孕手段。Condoms are an effective method of birth control if used with care.服用避孕药是最有效的避孕方法。The pill is the most efficient method of birth control.记下信用卡卡号，核对有效期限。Make a note of credit card numbers and check exp...