Signal ground
[計] 信號地線
?? 詞語組成解析
signal
['s?gnl]
n. 信號，暗號;預兆，征象;動機;導火線;
vt. 向…發信號;用動作（手勢）示意;以信號告知;
vi. 發信號;
adj. 顯著的，優越的;暗號的，作信號用的;
sign記號，信號+al表名詞 → 信號
ground
[ɡra?nd]
n. 地面，土地;基礎;范圍;陣地，戰場;
vi. 擱淺，停飛;著陸;
vt. 把…放在地上;在…的基礎樹立上;交給…基本知識;使…受初步訓練;
v. grind的過去式和過去分詞;
??? 情景例句
Will it cost for the transfer?
轉車要錢嗎？
How long will it take to have this radio fixed?
修理這收音機要多久？
recorded for the slumbering scientist the strength of a shock that was too weak to waken him,and the direction from which it came.
由于地震太弱而未驚醒科學家時，就為科學家記錄下了地震的強度和地震方向。