下列化合物属于多糖的是()
A.淀粉
B.树脂
C.树胶
D.果胶
E.蔗糖
参考答案:A, C, D
有以下程序 main( ) { char str[ ]="xyz",*ps=str; while(*ps) ps++; for(ps--;ps-str>=0;ps--) puts(ps);} 执行后输出结果是( )。
A.yz xyz
B.z yz
C.z yz xyz
D.x xy xyz
After trying hard, they _______ the hope of finding an effective way to solve the problem.
A.abandoned
B.released
C.discouraged
D.resigned