A:3A
B:1.1A
C:1.4A
D:1.8A
交朋友最重要的是讲“哥们儿义气”,“讲哥们儿义气”的朋友才是真正的朋友。( )
Sightseeing in this city is best done _______ by tour bus _______ by bicycles, you must choose one.
下列不属于光源的是( )
, ____