标准筛
参考答案:
筛孔孔径为25mm、13mm、6mm、3mm、1mm和0.2mm及其他孔径的方孔筛,3mm的圆孔筛。
读短文,判断下列句子正(Y)误(N)。
Look! This is a restaurant. It's not far from my school. It's clean and large. There is a TV in the room.
It's a colour TV. Many pictures and maps are on the wall. The map of China is on the right. This is a nice
room. Many tables and chairs are in the room. Many people are having their meals. I often have my lunch in
this restaurant. Its food is tasty. I like it very much.
( ) 1. My school is not far from this restaurant.
( ) 2. The school is small.
( ) 3. A TV is in the room.
( ) 4. The food is not tasty.
( ) 5. The map of China is on the left.
如图所示,是某小组成员利用能连续闪光的数码照相机拍摄到的四张小球运动的照片,其中受到平衡力作用的小球是( )
A.
B.
C.
D.