A beekeeper has a        to motivate the bees by leaving some honey in the hive—not so much in case that the bees stop working.

(2013·皖南八校第一次联考)—Do you believe that opportunities always ________ the prepared minds?—I couldn't agree more.

 It ________ me how we could improve the situation.

I soon found that the work I was doing had already been done by someone else.________，I was wasting my time.

 We'd better grow the plant in a ________ plastic box so that the children can see the roots growing.