34=15÷20=1216=75%=0.75；
故答案为：15，1216，75，0.75．
某同学家里的水稻生长不茂盛，叶色淡绿，稻穗短，籽粒不够饱满。请完成下面问题：
(1) 该同学家里的水稻缺乏两种营养元素，它们是___________( 填“N”“P”或“K”)。
(2) 该同学想购买含氮量最高的化肥，下列化肥他应购买___________ 。
A.NH4NO3 B.NH4HCO3 C.CO(NH2)2 D.NH4Cl
They considered ___ a computer, which was considered ___ a great help in their work.
A．to buy; to be
B．buying; being
C．to buy; being
D．buying; to be
