What are the layers of the tooth from hardest to softest?

How many moles of carbon atoms are there in 0.500 moles of C2H6?  

A casino employs a technician to repair slot machines that break down at an average of 6 machines per day (Poisson in nature). The casino operates 2000 slot machines on the casino floor. The technician can service an average of 9 machines per day, with a repair time distribution that approximates an exponential distribution. The technician’s cost is approximately $150 per day, while the cost associated with lost productivity from each machine breakdown is estimated at $120 per machine per day (or any fraction thereof).  If the casino hired a second technician at the same cost as the first what would be the cost savings (i.e. the change in the sum of lost productivity cost plus service cost)?

Young children who engage in longer periods of joint attention with their caregivers have relatively larger vocabularies at age 18 months than those of children with fewer such experiences. 

Which brain area is involved with planning and action selection prior to movement:

On average, infants produce their first true word around age ____________________.

What is the structure indicated by the arrow?    

What are some factors that might predict the variability among infants in the number of words they produce and the number of words they comprehend?

The prosodic characteristics of speech include ______________________________________.

Review your results from the photosynthesis experiment. What was something about your results that was unexpected? Explain why this was unexpected, making sure to discuss the results of your t-test and explain what they mean (i.e. you must use more words than simply, “the results were not significant/the results were significant” – explain what that means in this context!). (limit 2-4 sentences)