第9题: [单项选择]The term PROLONGED BLAST refers to(). A. a blast of from five to seven seconds' duration B. a blast of from five to six seconds' duration C. a blast of from four to six seconds' duration D. a blast of from six to seven seconds' duration 参考答案:C
第10题: [单项选择]镊取片码,不要()。 A. 夹住其卷角 B. 夹住其折边 C. 稳拿稳放 D. 互相碰击 参考答案:D