【单选题】Directions: Choose the right one from the four choices marked A, B, C or D. Our aim was to _____ whether or not vitamin D supplementation or deficiency in infancy could affect occurrence of t...
【简答题】You have been badly injured in a car accident. It is necessary to give you a blood transfusion because you lost a great deal of blood in the accident. However, special care must be taken in selecting ...