number of different pairs the teacher can choose= nCr (18+14, 2)=496
no. of opposite gender pairs possible= 14 (since there are only 14 boys)
probability = 14/496= 7/248
I would think its A. the rest of the options are for people that can stand still and focus.
A short term environment change would be drought, smog, volcanic eruptions, and blizzards. All because it only last for a small period of time and it can affect the way certain species will have to adapt to certain environments.
Answer:
The fertility rate measures the number of births per 1,000 women of childbearing age (ages 15 to 44) occurring in a particular year; birth rates refer to this measure within particular age groups.
Explanation: