单项选择题
The view from the 23rd floor of the sleek tower on Barcelona's Avenida Diagonal ______ opaquely as summer smog oozes across the Olympic landscape below.
单项选择题 Colour-blind people often find it difficult to ______ between blue and green.
单项选择题 He ______ that he has discovered a new planet.
单项选择题 As the clouds drifted away an even higher peak became ______ to the climbers.
