受膳食因素影响必须与结合的有机物分离才能被吸收的是______。
A．血红蛋白铁
B．血红素铁
C．非血红素铁
D．铁蛋白
E．转铁蛋白
参考答案：C
我国参加28届奥运会的男运动员138人，女运动员比男运动员的2倍少7人．男、女运动员一共多少人？
China ______ the WTO for more than 10 years, and it has brought great changes to it.
A．has joined
B．has been in
C．has become a member of
D．has joined in
