来源：

题目： $$\frac{49+49}{49+49^{2}}$$=

来源：

题目： If a and b represent positive single digits in the correctly worked computation above, what is the value of a + 2b?

来源：

题目： A circus clown is entertaining kids by making balloon animals. The clown can make any one the following animals: giraffe, dog, elephant, or monkey. The clown has five colors of balloons to choose from: red, yellow, blue, green, and purple. If the clown is just as likely to make any one of the animals and choose any one color, what is the probability that the clown will make a purple elephant?

来源：

题目： S1 = 7S2 = 10...Sn = 3n + 4For the sequence above, in which any term n is defined as 3n + 4, what is the value of n for the first term in the sequence to exceed 50?

来源：

题目：

Found in the wild only in Australia and New Guinea, powerful back legs with long feet distinguish kangaroos from other large mammals.

来源：

题目：

Every workday at dawn, the patriarch of one of the city's five richest families leaves his mansion and walks to city hall.

来源：

题目：

The declining number of graduate students majoring in engineering has resulted in less skilled engineers qualified to work in modern industries that have become increasingly high-tech.

来源：

题目：

In 1800, nearly 25 years after his discovering of methane gas, Alessandro Volta, the Italian physicist, had developed what would become known as the voltaic pile, the first electric battery.

来源：

题目：

Some museums regard themselves as keepers rather than owners of art, responsible for conserving it in the present and letting it go where circumstances are auspicious to do it in the future.

来源：

题目：

Regular maintenance such as inflating tires, replacing air filters, and tuning the engine can not only extend the life of a vehicle, but also can boost fuel efficiency.

来源：

题目：

Ranging from 1,500 to 2,300 kilograms, the body mass of the white rhinoceros is typically greater than the African hippopotamus.

来源：

题目：

High temperatures, beaches that are expansive, and active volcanoes attract close to seven million tourists to the Hawaiian Islands each year.

来源：

题目：

Foods high in tryptophan, an amino acid that is a precursor to serotonin, can help people to fall asleep by reducing anxiety, relaxing the brain, and in regulating the sleep cycle.

来源：

题目：

If a person wants to ascend up the corporate ladder, they have to know the rules of the game.

来源：

题目：

Discouraged by new data that show increases in toxic emissions from domestic factories, searches for alternative investment opportunities are being conducted by shareholders of the nation's leading manufacturing companies.