吲哚试验阳性的细菌是因为它能分解

A．葡萄糖

B．靛基质(吲哚)

C．色氨酸

D．枸橼酸盐

E．尿素酶

In relation to the turning circle of a ship，the term advance means the distance（）.

A.gained at right angles to the original course

B.gained in the direction of the original course

C.moved sidewise from the original course when the rudder is first put over

D.around the circumference of the turning circle