–There is little ________ at home. Let's go and buy some apples, pears and strawberries.–OK, we'll go to the supermarket in a minute.
A:chicken
B:fruit
C:vegetables
D:meat
设实数x,y,m,n满足x2+y2=1,m2+n2=3那么mx+ny的最大值是( )
读一读,选出发音不同的一项。
在研究电流跟电压、电阻的关系实验中,当研究电流与电阻的关系时()