春季植树时,移栽的树苗常被剪去大量的枝叶,这主要是为了降低植物的( )
A:呼吸作用
B:蒸腾作用
C:光合作用
D:分解作用
将Na2O2投入FeCl2溶液中,可观察到的现象是 ( )
Large amounts of food ______ wasted in our school everyday, but the poor in many countries ______ no access to drinking water.