刮板输送机是煤炭的承载机构，其牵引推动机构是绕过机头链轮和机尾链轮（也有采用带有过链沟槽的滚筒）而进行循环运动的无极闭合的刮板链。
参考答案：对
根据上下文内容在每个空格内填入一个适当的词。
B = Ben D = David
B: David, 1___________ do you often do on Saturday?
D: I 2___________ do my homework and sometimes I help Mum 3___________ housework.
B: How 4___________ Sunday?
D: I like to go 5___________. So I often go swimming on Sunday.
B: 6___________ your sister Nancy go 7___________ you?
D: No, she 8___________. She 9___________ shopping. She often 10 ___________ shopping with
my mother.
B: You have a happy weekend, David.
D: That's right.
积温
