设a=′′a′′，b=′′b′′，c=′′c′′，d=′′d′′，执行语句x=IIf（（ad），′′A′′，′′B′′）后，x的值为（　　）。

Clouds that form as small white flakes or scaly globular masses covering either small or large portions of the sky are（）.

A vessel proceeding along the bank of a river or channel has the tendency to（）.

______ it or not , his discovery has created a stir in scientific circles.

Generally speaking, suction heads require to be （） for high speed or large capacities than for low speed or small capacities.

Project（71）is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

Project ______is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

● Project（71）is an uncertain event or condition that, if it occurs, has a positive or a negative effect on at least one project objective, such as time, cost, scope, or quality.（71）

Once vessel has been cleared by Port Health or Immigration （）must proceed to appropriate berth or anchorage．

A salvor may be（）the whole or part of the payment due under Salvage Convention to the extent that the salvage operations have become necessary or more difficult because of fault or neglect on his part or if the salvor has been guilty of fraud or other dishonest conduct.

The Shipowner must not stow goods on deck（）there is a trade usage to that effect or the Charterer has given his express or implied consent.

A mark or place at which a vessel comes under obligatory entry，transit，or escort procedure is know as（）.