当某地气温年较差为20℃,地理纬度为30°N时,其大陆度为()k=(1.7⊿t/sinΦ)-20.4
A.1.7
B.47.6
C.19.6
D.20.4
参考答案:B
I am sad because I did ______ in the math exam.[ ]
A. bad
B. good
C. badly
D. well
室内消火栓出水方向宜向上或与设置消火栓的墙面成90°角。