Operant
n. 發(fā)生作用之人或物, 工作之人或物\\na. 動作的
??? 情景例句
I see him on the train every day but we are not on speaking terms.
我每天都在火車上見到他，但彼此沒有說過話。
A little neglect may breed great mischief.
小不忍則亂大謀。
It weighed nearly 500 pounds.
重達500磅左右。