锻丝上返卡环环抱稳定作用差的原因是没有()
A.卡环体
B.连接体
C.支托
D.固位臂
E.对抗臂
参考答案:A
—Do you often help your cousin with his English?
—No. He learns English by __________. [ ]
A. himself
B. yourself
C. herself
D. myself
2003-2007年,甲国平均每年比乙国少排放的碳总量为:()
A.30亿吨
B.48亿吨
C.55亿吨
D.60亿吨