— Is there ______ in today's TV news?
— Nothing serious.

The travelers arrived ______ Xi An ______ a rainy day.

I hear Ann______ drink a lot at the party.

Fred is ______ boy. He can swim and skit well.

If you keep______, you will be a very good swimmer one day.

Look! Mr. Wu______ football on the playground.

—______ do you usually go to work, Frank?
—By bike.

—Please give me a ______ when you get to HaiKou.
—All right. I'll tell you everything when I get there.

It' s time for lunch. Boys and girls, let's stop ______.

如图，已知直角梯形ABCD中，AD∥BC，AB⊥BC，AD＝2，AB＝8，CD＝10．(1)求梯形ABCD的周长；(2)动点P从点B出发，以1cm/s的速度沿B→A→D→C方向向点C运动；动点Q从点C出发，以1cm/s的速度沿C→D→A方向向点A运动；过点Q作QF⊥BC于点F．若P、Q两点同时出发，当其中一点到达终点时整个运动随之结束，设运动时间为t秒．问：①当点P在B→A上运动时，是否存在这样的t，使得直线PQ将梯形ABCD的周长平分？若存在，请求出t的值；若不存在，请说明理由.②在运动过程中，是否存在这样的t，使得以P、D、Q为顶点的三角形恰好是以DQ为一腰的等腰三角形？若存在，请求出所有符合条件的t的值；若不存在，请说明理由．