在嫁接梨树时,接穗应选用[ ]
A.味道涩,果实小的杜梨
B.果实大味道甜,但抗病力弱的鸭梨
C.抗病力强的野生梨的植株
D.生命力旺盛,生长快,但水果品质差的树种
答案:B
简述胰液的成分和它们的生理作用?
Is this your brother? What's ______ name? [ ]
A. his '
B. you
C. he
D. your