下列最容易引起大咯血的疾病是()
A.肺炎
B.肺结核
C.慢性支气管炎
D.肺肿瘤
E.肺梗死
参考答案:B
Reading is fun and helps you know __________ about the world
A.many
B.lots
C.a lot
D.a lot of
什么是进位和溢出?