— How many people are there in the hall?
— About two ______ people are listening to the speech.
A:hundred of
B:hundreds
C:hundred
D:hundreds of
计算:等于( )
西瓜堪称“瓜中之王”,原产于非洲,唐代时引入我国新疆,现在中国各地均有西瓜栽培,西瓜性寒,味甘甜;它有清热解暑、生津止渴、利尿除烦的功效.夏天是一个吃西瓜的季节,人们买了西瓜后经常会把西瓜放在冰箱中,这是为了( )
眼球中下列哪个结构含有对光线敏感的细胞( )