问题 单项选择题

下列关于指针的运算中,( )是非法的。

A.两个指针在一定条件下,可以进行相等或不等的比较运算

B.可以将一个空指针赋值给某个指针

C.一个指针可以加上两个整数之差

D.两个指针在一定条件下可以相加

答案

参考答案:D

解析: 指针变量如果指向同一个数组的元素,则可以进行比较,所以A) 是正确的。指针变量的赋值就是将一个变量地址赋给一个指针变量。并且指针变量可以是空值,即该指针不指向任何变量。B) 同样也是正确的。指针变量加/减一个整数是将该指针变量的原值(是一个地址)和它指向的变量所占用的内存单元字节数相加或相减。即C)也是正确的。如果两个指针指向同一个数组元素,两个指针是可以相减的,标识两个指针之间的元素个数。但是它们是不可相加的。

问答题 简答题
单项选择题

Egyptian wine has an extensive history within the history of Egyptian civilization. Grapes were not (1) to the landscape of Egypt, rather the vines themselves are (2) to have been imported from the Phoenicians, (3) the actual origins remain in (4) . What is known, is that (5) the third millennium BC, Egyptian kings of the first (6) had extensive wine cellars, and wine was used extensively in the temple ceremonies. The main (7) of wine in Egypt, took place between the king, nobles, and the priests in temple ceremonies, and is (8) by numerous painted relief’s, and other (9) evidence. The vineyards of ancient Egypt, were quite different from the modern methods of wine making today. (10) viticulture ( or wine making), ceased to (11) an exclusively ceremonial purpose, the Egyptians began to experiment with simple structures for their vines to train on, (12) found a way to train their vines so they were easy low (13) bushes, and found ways for the soil to (14) more moisture for the vines. Egyptian wine making experiments included the use of different wine presses, adding heat to the must ( the grape juice ready for fermentation) (15) make the wine sweet, and differences in vat types and materials. The (16) finished product of wine, was poured through a cloth filter, and then into earthenware jars, (17) they would be sealed with natural tar and left to (18) . The Egyptians kept accurate records of their vintages, and (19) of their wines, each jar of wine was clearly (20) with it’s own vintage, and quality.

16()

A.final

B.end

C.eventual

D.ultimate