The St.Lawrence and（）together form an

1、The cylinder liner forming the cylinde

The cylinder liner forming the cylinder wall and the inside of the water jacket is called a（）Adry linerBwet linerCjacket linerDcorrugated liner

2、People working together in an office u

People working together in an office used to ____________.A talk more about handwritingB take more notes on workdaysC know better one anothers handwritingD communicate better with one another

3、An engineer, together with some motorm

An engineer, together with some motormen （）to help in the repair work.AsendBsendsCwas sentDwere sent

4、Sludge may form in the crankcase of an

Sludge may form in the crankcase of an air conditioning compressor as a result of （）.Abubbling refrigerantBoverheating and oxidationClowered operating temperaturesDreducing the cloud or flash point

5、The type of joint formed when an edge

The type of joint formed when an edge of one plate is laid over the edge of the plate to which it is riveted is a（）.Agrip jointBstrap jointCthread jointDlap joint

6、● The Internet is an open system, and

● The Internet is an open system, and most information is available to everyone. It is very important to add (74) to existing system for protecting the secret information.(74)A Web pagesB modemC securityD network