房地产投资者对系统风险不易判断和控制，其系统风险主要包括( )。 A．通货膨胀风险

脆性材料拉伸时不会出现（）。

A.伸长

B.弹性变形

C.断裂

D.屈服现象

请补充函数fun()，该函数的功能是将字符串tt中的大写字母都改为对应的小写字母，其他字符不变。例如，若输入“Are you come from Sichuan”，则输入“are you come from sichuan”。
注意：部分源程序给出如下。
请勿改动主函数main和其他函数中的任何内容，仅在函数fun()的横线上填入所编写的若干表达式或语句。
试题程序：
#include＜stdio.h＞
#include＜string.h＞
#include＜conio.h＞
char *fun(char tt[])

int i;
for(i=0;tt[i];i++)

if((tt[i]＞=’A’)&&( 【1】 ))
【2】 ;

return ( 【3】 ) ;
main()

char tt[81];
printf("\nPlease enter a string:");
gets(tt);
printf("\nThe result string is: \n%s",
fun(tt));

某商场2001年销售收入2300万元，租赁收入200万元，营业外收入50万元，业务招待费80万元，该商场下列作法正确的是( )。

A．按80万元作为税前扣除的业务招待费

B．按9.9万元作为税前扣除的业务招待费

C．按12.5万元作为税前扣除的业务招待费

D．纳税调增额69.5万元

什么部件控制APU引气到气源系统？（）

A.APU单向活门

B.调节活门

C.引气活门

D.SCV

Mr. Faugel was convinced that student nervousness had affected their scores; to reduce the anxiety of these students who had already been tested, he gave 22 of them a beta blocker before readministration of the test. Their scores improved significantly. The other 8 students (who did not receive the beta blockers) improved only slightly. Second-time test-takers nationwide had average improvements which were similar to those in Faugel’’s non-beta blocker group. Beta blockers are prescription drugs which have been around for 25 years. These medications, which interfere with the effects of adrenalin, have been used for heart conditions and for minor stress such as stage fright. Now they are used for test anxiety. These drugs seem to help test-takers who have low scores because of test fright, but not those who do not know the material. Since there can be side effects from these beta blockers, physicians are not ready to prescribe them routinely for all test-takers.

According to the passage,________.

A．all people can take beta blockers

B．beta blockers are widely prescribed

C．beta blockers work only on test anxiety

D．beta blockers work only to improve test scores if the test-taker truly knows the material