n. 管,管状物;电子管;地铁;电视机;
vt. 把…装管;把…弄成管状;用管输送;
vi. 乘地铁;不及格;
tub- 表”管道”
🗣️ 情景例句
No ... OK ...
不是……好……
Listen and repeat.
先听,然后再重复一遍。
Although mankind has undergone no general improvement in intelligence or morality, it has made extraordinary progress in the accumulation of knowledge.