铲斗最佳值由()因素来决定。
A.运载设备的容量
B.采场条件
C.矿石硬度
D.松散程度
E.货源
参考答案:A, B, D
X、Y、Z均为元素周期表中的前20号元素,且可形成化合物XYZ4;三种元素原子序数之和为44,且均不在同一周期,但Y和Z同主族,下列有关推断中正确的是( )
A.XYZ4是一种微溶于水的盐,且X与Y可形成离子化合物XY
B.XYZ4是一种可溶于水的盐,且X与Y可形成离子化合物XY
C.XYZ4是一种易溶于水的盐,且Y与Z可形成共价化合物YZ
D.XYZ4是一种离子化合物,且Y与Z可形成离子化合物YZ2
One day while a girl was walking in the woods she found two starving songbirds. She took them home and put them in a small (16) She cared for them and felt great love for them. Once the (17) and per of the two birds flew from the cage. Therefore, (18) he flew close, she grasped him (19) She felt glad, but suddenly she felt the bird go limp. She opened her hand and (20) in horror at the dead bird. She noticed the other bird moving back and forth on the edge of the cage. She could feel his great need for (21) She lifted him from the cage and (22) him softly into the air. The bird circled once, twice, three times. The girl watched delightedly at the bird’ s enjoyment. Her heart was no longer (23) with her loss. Suddenly the bird flew closer and (24) softly on her shoulder. It sang the sweetest melody that she had ever heard. The fastest way to (25) love is to hold on it too tightly, while the best way to keep love is to give it WINGS!
Ⅱ. 完形填空
A.freedom
B.food
C.love
D.space