二元一次方程x+y=5的正整数解有( )。
,,,
Although he has not gone to college,he shouldn't ________ studying for his degrees.
A.be prevented
B.be stopped
C.be kept from
D.be protected from
西湖名联中最有名的莫过于杭州"西湖天下景"亭柱上的"山山水水处处明明秀秀;晴晴雨雨时时好好奇奇".请问这副楹联挂在哪处景点?()
A、中山公园
B、湖心亭
C、郭庄
D、风波亭