More than 70 percent of developing country exports are invoiced in ________

Which of the following does NOT represent a social media network that has stood the test of time?

A) Facebook B) LinkedIn C) MySpace D) YouTube

Assuming that Si is a binary variable, write the constraint(s) for the second restriction

You have been asked to select at least 3 out of 7 possible sites for oil exploration. Designate each site as S1, S2, S3, S4, S5, S6, and S7. The restrictions are: Restriction 1. Evaluating sites S1 and S3 will prevent you from exploring site S7. Restriction 2. Evaluating sites S2 or S4 will prevent you from assessing site S5. Restriction 3. Of all the sites, at least 3 should be assessed. A) S2 + S5 ? 1 B) S4 + S5 ? 1 C) S2 + S5 + S4 + S5 ? 2 D) S2 + S5 ? 1, S4 + S5 ? 1