We are going to play table tennis________.
A:at tomorrow
B:in next Sunday
C:yesterday
D:the day after tomorrow
—It's cold today. Put on your____, Tony!
—OK, Mum.
若∠α=35°19′,则∠α的余角的大小为____ .
(理)已知随机变量ξ满足Dξ=2,则D(2ξ+3)=( )
一种抗生素为粉末状固体,每瓶含0.5g,注射时应配成质量分数为20%的溶液,则使用时每瓶至少需加入蒸馏水( )