‌Which of the following descriptions of gray numbers is correct?‏ A: A grey number is a kind of uncertain number which exact value and the range are unknown. B: A grey number is a kind of uncertain number which exact value is unknown but the range of the number is known. C: The value range of the gray number can only be an interval. D: Black and white numbers are not gray numbers.

Which of the following statements is ? ( ) A: Java provides two primitive types for storing floating-point numbers in memory float and double. B: A floating-point number is a number with a decimal point. C: Variables of type float represent single-precision floating-point numbers and have seven significant digits. D: Variables of type float represent double-precision floating-point numbers; these require twice as much memory as double variables.

Could you please tell me the____for Class 1 and Class 2? A: rooms numbers B: rooms number C: room's numbers D: room numbers

中国大学MOOC: Among the following numbers, which one is seen as a yang number in the classic I-Ching?

A number dial lock has four dials. Each dial has 10 numbers from 0 to 9. How many four digit numbers can these four dials make up.( ) A: 4 B: 9999 C: 10000 D: 10