题目

（2010·辽宁东北育才学校高三第一次模拟） 5、______ his telephone number or e-mail address, she had some difficulty ____ in touch with John. A. Not knowing; getting    B. Not having known; to get   C Knowing not; to get      D. Having not known; getting 答案：A鼠的毛色类型由等位基因B、b控制，现有甲、乙黑毛雌鼠分别与褐毛雄鼠（丙）交配，甲三胎生出9只黑毛幼鼠和7只褐毛幼鼠；乙三胎生出19只黑毛幼鼠，则甲、乙、丙三只鼠的基因组成依次为                             A．BB、Bb、bb       B．bb、Bb、BB      C．Bb、BB、bb      D．Bb、bb、BB