When __________is produced, complete closure of the articulators is involved so that the air stream cannot escape through the mouth．

[单选题]So involved with their computers _______ that leaders at summer computer caps often have to force them to break for sports and games.A． became the cildren B become the children C had the children become D do the children become

[单选题]When the water produced from most evaporator is supplied for drinking purpose, it must be treated to ensure it is biologically pure and _____.A．slightly acidicB．slightly alkalineC．no saltyD．slightly bitter

[单选题]He would once in a whilelose his temper when he found himself involved in a

[单选题]In competitive markets, when the efficient quantity is produced, the least

[单选题]When the starting air valve closes on one cylinder, another starting air valve has （） opened on another cylinder whose piston has just commenced its downward stroke.A . justB . nearlyC . merelyD . already

[单选题]［A］ as ［B］ when ［C］ if ［D］ so

[单选题]So involved with their computers( )that leaders at summer computer camps of

[单选题]So involved with their computers( )that leaders at summer computer camps of

[单选题]_____ the 2008 Olympic Games, the air quality in Beijing would not be so go

[多选题]The combination of sea/air transportation has in itself some advantages，suc