—Haven't seen you for ages! Do you still work in Xi'an?
—________. It's four years since I worked there.
A:No, I don't.
B:No, I haven't.
C:Yes, I do.
D:Yes, I have
已知:m, n是两个连续自然数(m<n),且q=mn, 设p=q+n+q-m则p( )
只含铜和氧两种元素的固体样品9.0g,测得其中铜元素的质量为8.0g.已知铜的氧化物有CuO和Cu2O两种,下列说法正确的是( )
光明小学四年级同有10位老师和310名同学去春游.已知大车可坐60人,租金900元,小车可坐40人,租金720元,怎样租车最省钱?需要多少元?