A: How was your day off, Tina?
B: Oh, it was awful.
A: Really?  1
B: Well, we wanted to go camping, but the weather was terrible.  2
A: Oh, that's too bad. Then what did you do? Did you watch TV at home?
B: No.  3   . It was boring.
A: Sounds terrible, Tina.
B:   4
A: I think I had great fun. I went to the museum and met a famous actor.  5      And I got his autograph.
B: That sounds wonderful.

下列说法正确的个数为（   ）

①对于不重合的两条直线，“两条直线的斜率相等”是“两条直线平行”的必要不充分条件；

②命题“∀x∈R，sinx≤1”的否定是“∃x₀∈R，sinx₀＞1”；

③“p且q为真”是“p或q为真”的充分不必要条件；

④已知直线a，b和平面α，若a⊥α，b∥α，则a⊥b．

某同学用如图所示装置做“探究功和物体速度变化的关系”实验时，先调整木板的倾角使小车不能连接橡皮筋时恰能在木板上匀速下滑，探后第一、三次分别用一条、三条相同的橡皮筋做实验，且两次橡皮筋的伸长量相同，若第一次实验中合外力对小车所做的功为W，则第三次实验中合外力对小车所做的功为____．由本实验可得出的结论是：____．