给出下列四个命题：

①若集合A，B满足A∩B=A，则A⊆B；

②给定命题p，q，若“p∨q”为真，则“p∧q”为真；

③设a，b，m∈R，若a＜b，则am²＜bm²；

④若直线l₁：ax+y+1=0与直线l₂：x﹣y+1=0垂直，则a=1．

其中正确命题的个数是（　　）

①它是社会主义的根本经济特征和社会主义经济制度的基础

②其主体地位体现在国有资产在社会总资产中占优势

③公有制经济控制国民经济命脉，对经济发展起主导作用

④要增强公有制的主体地位，必须推动国有资本更多投向关系国家安全和国民经济命脉的重要行业和关键领域

读图，回答下列问题。

    There is a p____near our school. We can see many trees and flowers there. Some flowers are red, and some are y____. We can see a hill behind the park, too. At the foot of the hill we can see a r____. There are some boats on it. Children like to go there. It is Monday today. There are many young pioneers(少先队员)in the park. Some are walking and singing. S____are dancing and p____ games. Ann and h____ sister Kate are flying a k____. Tom and his brother Sam are t____a frisbee (飞盘). Their lather and mother are sitting u____ a tree. All the people are h____a good time.

舍：<shě> ____     <shè> ____