⑴____A. hand B. face C. father
⑵____A. dog B. one C. mother
⑶____A. big B. pig C. fifteen
⑷____A. duck B. fourteen C. fruit
⑸____A. ten B. eleven C. desk
orange water apple grapes banana hamburger hot dogs juice
A: ____
B: ____
C: ____
D: ____
若代数式x-2在实数范围内有意义,则x的取值范围是( )
下列两个实验中体现出的共同的物理思想方法是( )