If an obligatory duty payer fails to fulfill his duty payment obligation, the bank issuing a letter of duty guarantee for him has the obligation to pay the duty.（)

A．urrent flowing from DUT into system

B．urrent flowing from the test system into DUT

C．urrent flowing from a higher voltage to a Lower voltage

D．以上都不是

专性寄生虫(obligatory parasite)

A.fiduciary

B.distribution

C.compulsory

D.trademark

A．Russian has an obligatory for gender.

B．Russian has fewer grammar rules.

C．Russian has different sentence structures.

D．Russian is difficult to translate.

A.0.5m±0.1m

B.1~2m

C.（200~400）mm

D.（900±10）mm

A、Voluntary

B、Compulsory

C、Obligatory

D、Imperative

A.Way point

B.Receiving point

C.Reporting point

D.Closest point

A.：

B.5 years

C.3 years

D.2 years

E.1 year