A:变形虫、水绵、香菇
B:烟草、烟草花叶病毒、大肠杆菌
C:酵母菌、灵芝、豌豆
D:小麦、番茄、大豆
若bk<0,则直线y=kx+b一定通过( )
实验材料与用具:适宜浓度的H2O2溶液,蒸馏水,3.5%FeCL3溶液,0.01%过氧化氢酶溶液,恒温水浴锅,试管.
–David, is that _____ English teacher?
--Yes, he is ___. He is very caring.