①若实数a，b，c满足a+b+c=3，则a，b，c中至少有一个不小于1

②若z为复数，且|z|=1，则|z﹣i|的最大值等于2

③任意x∈（0，+∞），都有x＞sinx

④定积分 ${\displaystyle \int {}_0^{\sqrt{\pi }}}\sqrt{\pi -x^2}$ dx= $\frac{{\pi }^2}{4}$ ．

用____可以围成一个平行四边形．

:We're going camping in the forest this weekend. What shall we do then?

:Let's go hiking and collect leaves.

:Sounds great! I want to ____stars(星星)at night，too. That's beautiful.

:I'd like to take some ____. There're many flowers in the forest.

:Good idea! But first，we should ____the tent on the grass. And l want to catch fish in the river. Because your mum ____eating fish.

:Thanks，dear! And we can build campfire and cook fish ____our tent.

建设服务政府要加强政府公共服务职能。以下体现履行这一职能的是（    ）