蔗糖（C12H22O11）是生活中最常用的甜味品。它是由_________种元素组成，其分子中氢、氧原子个数比为____________。
3；2∶1
My friends and I are making an area to encourage birds _________.
A．come and feed and lay their eggs safely
B．to come and feed and lie their eggs safely
C．to come and feed and lay their eggs safety
D．to come and feed and lay their eggs safely
已经发生私下交易的农村房屋如何确定所有权主体？
