气泡: bubble, blister (in metal), (of beverages) sparkling, carbonated...
形成: to form, to take shape...
捆: tie; bind; bundle up...
难题: difficult problem...
随即: immediately, presently, following which...
缺席: absence, absent...
激素: hormone...
锤子: hammer...
安全: safe, secure, safety, security...
跑车: racing bicycle, sporting bicycle, sports car, logging truck, on the job (of a train conductor)...
