We are all sorry to hear that the number of the Asian tigers _____ getting _____ these years. [ ]

A. is, fewer

B. is, smaller

C. are, less

D. is, bigger

巴豆、苍耳子、蓖麻子的主要毒性成分是（）

A.汞

B.毒蛋白

C.皂苷

D.强心苷

E.内酯