把21本科技书平均分给4个小组,每个组分到______本,还剩______本.
21÷4=5(本)…1(本),
答:每个组分到5本,还剩1本.
故答案为:5,1.
He ______very important information in his report. That was why he was criticized by his boss.
A.left out
B.left behind
C.left off
D.left for
X线照片产生灰雾的原因,主要有()
A.胶片本底灰雾
B.焦点外X线
C.显影处理
D.被检体产生的散射线
E.胶片分辨率