求OG12版，谁有啊？我7月6号考试，希望能有人转让

jennyruxin

求OG12版，谁有啊？我7月6号考试，希望能有人转让。MSN是ruxinsweet(A) hotmail.com, tel 13910791892

jennyruxin

10.    719-!-item-!-187;#058&000515
Of the 800 students at a certain college, 250 students live on campus and are more than 20 years old.  How many of the

800 students live on campus and are 20 years old or less?

(1)  640 students at the college are more than 20 years old.

(2)  60 students at the college are 20 years old or less and live off campus.

这种题目怎么做啊 ？那位大侠教教