一、單項(xiàng)選擇題（本大題共20小題，每小題1分，共20分）

在每小題列出的四個(gè)備選項(xiàng)中只有一個(gè)是符合題目要求的，請(qǐng)將其代碼填寫在題后的括號(hào)內(nèi)。錯(cuò)選、多選或未選均無(wú)分。

1．下面哪種設(shè)備是輸入設(shè)備？(     )

A.鍵盤                                                      B．打印機(jī)

C．顯示器                                                D．投影儀

2．與十進(jìn)制39等值的二進(jìn)制數(shù)是(     )

A.00100111                                               B.01001001

C.10100111                                               D.01011000

3．設(shè)有 int a=3，b=-4;表達(dá)式(a<b)? a b：（a-b，b 4，a-=b 4）的值是(     )

A.-1                                                          B．0

C．3                                                        D．7

4．設(shè)有int a=3,b=-4，c=5;表達(dá)式a=b=c=6 3/5的值是(     )

A.3                                                           B．4

C．6                                                        D．6.6

5．以十進(jìn)制無(wú)符號(hào)形式輸出整數(shù)的格式說(shuō)明符是(     )

A. %u                                                       B．% x

C．%o                                                     D．%d

6．下列程序段執(zhí)行后的輸出結(jié)果為

int i =-1;

if(i<=0)    printf(＂* * * * \n＂);

else printf (＂%%%%＼n＂);  (      )

A. * * * * c                                               B.% % % %

C. % % % % c                                          D.** * *

7．執(zhí)行下面程序段后的y值是

int y=l, x=5；

if(x<0)y=-1；

if(x>=0)y=0;  (      )

A.-1                                                          B．0

C．1                                                        D．5

8．執(zhí)行while（表達(dá)式）結(jié)構(gòu)循環(huán)的條件是(     )

A．當(dāng)表達(dá)式的值為0時(shí)                           B．僅當(dāng)表達(dá)式的值為l時(shí)

C．當(dāng)表達(dá)式的值為非0時(shí)                       D．當(dāng)表達(dá)式的值不為1時(shí)

9．下面程序段的輸出結(jié)果是

a=100;

while (a>120)

a= a l;

printf (＂%d", a);  （      ）

A.100                                                       B．101

C．120                                                     D.121

10.下面程序執(zhí)行后，i的值是

main()

{   int  a[5]={1,2,3,4,5），i =2;

printf (＂%d＂，a[ i ])；

} (      )

A．1                                                        B．2

C．3                                                        D．4