题目

Our new teacher is patient, kind, humorous, caring, and ________ strict too. We really learn a lot from her. A. though        B. besides              C. yet                  D. therefore 答案：C4．若14400所有正因数从小到大构成的数列d1，d2，…，dn，则Sn=$\frac{1}{{d}_{1}}$+$\frac{1}{{d}_{2}}$+…+$\frac{1}{{d}_{n}}$=$\frac{51181}{14400}$．