在河岸边开挖隧洞,在基坑上下游修筑围堰,施工期间河道的水流由隧洞下泄,这种导流方法称为()。
A.明渠导流
B.隧洞导流
C.涵管导流
D.束窄河床导流
参考答案:B
检查EFI系统中的高阻值型喷油器电磁线圈.其电阻应为()。
A.12~16欧;
B.30~35欧;
C.0.5兆欧;
D.2~5欧
A “full service” Loran-C receiver will provide().
A.matching pulse rates of at least 20 stations
B.an automatic on-and-off switch
C.a horizontal matching of all delayed hyperbolic signals
D.automatic signal acquisition and cycle matching