Volcanics
火山岩
🗣️ 情景例句
Hobbies are supposed to be relaxing.
业余爱好应该是令人放松的。
There is a crook(=affliction,trial) in the lot of every one.
人生总有倒楣事；人生总有不如意处。
and by measuring the time interval between the taps and the receipt of the echoes, the depth of the sea at that point can be calculated.
测出回声间隔的时间，便可算出该处海洋的深度。