A:①②③
B:①②④
C:①③④
D:②③④
如图,在△ABC中,AB=20cm,AC=12cm,点P从点B出发以每秒3cm速度向点A运动,点Q从点A同时出发以每秒2cm速度向点C运动,其中一个动点到达端点,另一个动点也随之停止,当△APQ是以PQ为底的等腰三角形时,运动的时间是 ____ 秒.
My friends thought they had made things very smooth for me, but I felt there was still much to ________ with.