（1）-（+5）和-（-5）分别表示什么意思？你能化简它们吗？ （2）+（+5）

某位外国朋友想考察我国境内最早的人类遗址，他应该去（   ）

A．云南元谋

B．浙江河姆渡

C．北京周口店

D．陕西半坡

从A、B、C、D四个选项中找出一个错误的并改正

1. He and his friends had a fun playing basketball.                          

              A                 B    C            D

2. Tom borrowed these new shoes to Jim last night.                         

                A           B      C             D

3. He didn't went to school last week.                          

         A          B   C                    D

4. Jack went to see his teacher and asks some questions.                            

                    A   B                            C    D

5. He drove his new car and stoped in the street yesterday.                                 

             A          B                   C                 D

当前PU机中的二级cache存储器是直接挂在( )。

A．PCI总线上

B．ISA总线(AT)总线上

C．CPU局部总线上

D．EISA总线上

关于消化性溃疡的临床症状不正确的是（）

A.胃溃疡多为餐后疼

B.十二指肠溃疡多为空腹和夜间疼

C.消化性溃疡病人均有上腹疼

D.十二指肠溃疡易发展为穿透性溃疡

E.球后溃疡易发生大出血

说明光合细菌的培养条件。