Using the same cutting board for raw chicken and raw beef can be cross-contamination or cross infection

Which of the following statements is not correct? 1) trade allows for specialization. 2) trade has the potential to benefit all nations. 3) trade allows nations to consume outside of their production possibilities curves. 4) absolute advantage is the driving force of specialization.

Skychefs, inc. prepares in-flight meals for a number of major airlines. one of the company's products is grilled salmon in dill sauce with baby new potatoes and spring vegetables. during the most recent week, the company prepared 4000 of these meals using 960 direct labor hours. the company paid these direct labor workers a total of $19,200 for this work, or $20.00 per hour. according to standard cost card for this meal, it should require 0.25 direct labour-hours at a cost of $19.75 per hour.1. what is the standard labor-hours allowed (sh) to prepare 4,000 meals? 2. what is the standard labor cost allowed (sh x sr) to prepare 4,000 meals? 3. what is the labor spending variance? 4. what is the labor rate variance and the labor efficiency variance?

Russell's study compared gpa of those students who volunteered for academic study skills training and those who did not elect to take the training. he found that those who had the training also had higher gpa. with which validity threat should russell be most concerned?