现有黑色短毛兔和白色长毛兔,要育出黑色长毛兔。理论上可采用的技术是()①杂交育种②基因工程③诱变育种④克隆技术
A.①②④
B.②③④
C.①③④
D.①②③
参考答案:D
Mr. Zhang, our math teacher, is strict with students and serious in teaching work, so he ____.
A.thinks highly of
B.is thought highly
C.is highly thinking
D.is highly thought of
甲、乙两物体质量相等,当甲物体温度升高10℃,乙物体温度升高20℃时,甲物体吸收的热量是乙物体吸收热量的2倍,则甲的比热是乙的比热的( )