表面活性剂能够形成泡沫,并能稳定和保护泡沫的作用称为()。
A、乳化作用
B、消泡作用
C、发泡作用
D、润滑作用
参考答案:C
The wrong you have done to him is terrible,________, in my opinion,you should apologize to him.
A.which
B.that
C.what
D.for which
有下列程序: main() {int k=5; while(--k) printf("%d",k-=3); printf("\n");} 执行后的输出结果是( )。
A.1
B.2
C.4
D.死循环