— _____
— It is August 1st.
A:What was the date?
B:When is today?
C:What's the date today?
D:What day is it today?
观察下列单项式:a,-2a2,4a3,-8a4,16a5……,按规律第个单项式是____ .(是正整数)
对代数式3a和2a﹣b,分别举出两个具有相应数量关系的实例.
下列说法正确的是 ( )