Shall we go and help them with their work—-We’d better not. They said we’d just be ______ if we tried to help.

Though Mandela﹙曼德拉﹚____27 years in prison﹙监狱﹚, he thought it meaningful.

Yesterday I bought a robot, which could help me to clean the floor.—Really That’s great. I’ll buy .

1Five _______ students fromdifferent schools took part in the English contest last Saturday.

下列词语中加线的字,读音全都不相同的一项是(　　)