等腰梯形的两条对角线( )。
相等
Mrs. White found her husband surrounded by letters and papers and _____ very worried. [ ]
A. look
B. looks
C. looking
D. to look
(l)下列说法正确的是
A.密闭房间内,温度升高,空气的相对湿度变大
B.密闭房间内,温度越高,悬浮在空气中的PM2.5运动越剧烈
C.可看作理想气体的质量相等的氢气和氧气,温度相同时氧气的内能小
D.系统的饱和汽压不受温度的影响