人体呼出的气体能使澄清的石灰水变浑浊，是因为人体呼出气体中含有较多的（ ）
如图，直线y=-2x+4与x轴，y轴分别相交于A,B 两点，C为OB上一点，且∠1=∠2，则S△ABC=（ ）
选择合适的句子，补全对话。（有两项是多余的）
A. What did you do yesterday?
B. Where did you go yesterday?
C. How many children were there at the party?
D. Yes, he did.
E. Why did you visit Mike?
F. No, they weren't.
G. How many children are there at the party?
A:Hello, Liu Yun. ____
B:I visited Mike.
A:____
B:Because it was his birthday yesterday.
A:Did he have a birthday party?
B:____
B:There were fifteen children at the party.
A:Were Mike's parents at home?
下列物质经泌尿、排汗和呼吸三条途径中的两条途径排出体外的是（ ）
①二氧化碳 ②无机盐 ③食物残渣 ④尿素
