A:Yes, he does.
B:No, he is talking on the phone.
C:Yes, he wants to read a book.
元素和化合物是细胞的物质基础,下列叙述正确的是( )
近年来,影响北京的浮尘、扬沙和沙尘暴天气表现出加剧的趋势,但大多数沙源却不是来自北京,其沙源最有可能来自:
猜灯谜。
9÷____=3
18÷____=3
____÷4=2
20÷____=4
____÷6=5
16÷____=4