—We plan to go out for a picnic next weekend. Would you like to come along? 

—______. It's my favorite.[ ]

A. Enjoy yourself

B. It doesn't matter

C. You're welcome

D. That would be very nice

（6分）根据题目要求完成下列各图．

（1）如图甲为用螺丝刀撬图钉的示意图．画出动力F₁的力臂l₁和阻力F₂的示意图．

（2）如图乙所示，光沿AO方向从水中射向空气．画出它的反射光线和折射光线．

（3）如图丙所示，标出通电螺线管周围磁感线方向和小磁针的N极．