.The possible benefits of cloning are numerous , for______ producing human tissues and organs for transplant, and for preserving endangered animal species to name but two.

A．artificially

B．materially

C．scientifically

D．medically

—Remember this, children. ______ Careful you are, ______ mistakes you will make.  

—We know, Miss Gao.  

A. The more; the more        

B. The fewer; the more  

C. The more; the fewer        

D. The less; the less