所有CD-ROM光盘只能读,不能写( )
A.是
B.否
参考答案:A
Many a student ____ going to have themselves ____ in the hospital.
A.is ; to examine
B.are ; examine
C.is ; examined
D.are ; examining
有甲、乙、丙、丁、戊五只猫,其中甲、乙、丙都是短毛,丁和戊是长毛,甲和乙是雌性,其余都是雄性。甲和戊的后代全部是短毛,乙和丁的后代长毛、短毛都有。欲测定丙猫的基因型,与之交配的猫应选择()
A.甲猫
B.乙猫
C.丁猫
D.戊猫