第26题: [单项选择]So______ after she learned the good news that she could hardly fall asleep that night. A. excited the mother was B. the mother was excited C. was the mother excited D. excited was the mother 参考答案:D
第27题: [单项选择]由某表面活性剂司盘(HLB＝4.7)和表面活性剂吐温60(HLB＝14.9)组成乳化剂，其 HLB值愈为10.3，求吐温的重量百分比 A. 50.5% B. 52.9% C. 55.5% D. 54.9% E. 59.2% 参考答案:D 答案解析:混合乳化剂的HLBab＝(HLBa×Wa＋HLBb×Wb)/(Wa＋Wb)，其中吐温的重量百分比为Wb，根据题意，10.3＝ 4.7×(1－Wb)十14.9×Wb，可得Wb＝ 54.9%。选D。
