Whatisthepurposeofareliefvalve?()
A. tofill2tanksatthesametime
B. tousepumpatahigherpressure
C. toreturnliquidtosuctionsideifdischargevalveisclosed
D. Alloftheabovearetrue
查看答案
单谐振回路谐振放大器的短形系数K0.1等于()。
A. 2.35
B. 3.15
C. 10
Whichofthefollowingpumpsbelongstocentrifugalpump?()
A. Pistonpump
B. Screwpump
C. Diffuserpump
D. Water-ringpump
在同步调谐的多级单调谐回路放大器中,当级数增加时,放大器的选择性()。
A. 变坏
B. 变好
C. 增宽
D. 变窄
ThecertificateofaLloyd’ssurveyor()likelytobeacceptedbythecourtasconclusivetoshowthatthecarrierhasexercisedduediligencewhenitrelatestoacaseinwhichhehasbuiltorboughtavesselinthefirstinstance.
A. are
B. is
C. have
D. has