观察图，按要求填空。 （1）l= cm （2）G=___________N （

        much progress you have made, you should be modest．

A．No matter

B．How

C．Whatever

D．However

By looking at a problem in as many ways as possible,creative thinkers can find solutions that

would_________remain invisible. [ ]

A. otherwise  

B. yet  

C. already  

D. forever

自动液位计无法通信的原因有（）。

A.未设置油罐参数

B.端口设置错误

C.使用WindowsMe

D.油位过低

胶粘剂和防烧剂各用在什么部位？