— I hear Leo will leave for Korea for a meeting.
— Really? Do you know when he _______.
A:will start
B:to start
C:started
若实数x,y满足x2+y2≤1,则|2x+y﹣2|+|6﹣x﹣3y|的最小值是____ .
轮作是在同一块地上按预定的种植计划,轮换种植不同的作物,这样做可以提高作物产量。下列说法解释不够恰当的一项是()