My plant _______________ two green leaves.[ ]
A. have
B. is
C. has
答案:C
合成血红素的反应在胞液中进行的是()
A.原卟啉原的生成
B.ALA的合成
C.原卟啉原Ⅲ的合成
D.血红素的生成
E.原卟啉Ⅸ的生成
All the money he had was ______, so he had to make a living by begging.[ ]
A. used up
B. taken up
C. stayed up
D. brought up