If a scientist wants to design an experiment to measure the effect of vitamin c on colds, which of the following would be an appropriate placebo?
a. half the recommended daily amount of vitamin c
b. a sugar pill that does not contain vitamin c
c. the recommended daily amount of vitamin d
d. the recommended daily amount of vitamin c

b.  A sugar pill that does not contain Vitamin C

Explanation:  

It has to be a sugar pill because a placebo (or dummy pill) is an inert (inactive) substance, typically a tablet, capsule or other dose form that does not contain an active drug ingredient.

glacial erosion, the picking up and movement of earth beneath a glacier, is also referred to as plucking. erosion and transportation of individual pieces of bedrock, especially large "joint block occur as a result of this glacial erosion. plucking is type of erosion in which rocks become frozen into the bottom and sides of the glacier.as the glacier moves downhill it 'plucks' the rocks frozen into the glacier from the ground.