in case
if 如果；若
In case he arrives be fore I get back，please ask him to wait．如果 我回来前他就到了，请叫他等我。
In case it rains，do not expect me． 如果天下雨，就不要指望我来了。
in case of in the event of； as for要是；在… 时（候）In case of fire，the alarm bell．如遇火灾，即按警铃。
In case of any difficulty，call me at once．如有任何困难，立即找 我。
In case of illness， you must consult a doctor．假使有病，你必须请医 生诊治。