颜色的冷暖感主要是由（）影响。
A、颜色纯度
B、颜色亮度
C、颜色的黑白度
D、颜色的色调
参考答案：D
We're still at the airport. If it weren't for the delayed flight, we _____ the concert right now. [ ]
A. can be enjoying
B. must have enjoyed
C. would be enjoying
D. should have enjoyed
桥式转载机的组成部分有哪些？
