迁延性腹泻的病程是（）
A.<2周
B.2周至2个月
C.<1周
D.>1个月
E.>2个月
参考答案：B
He is very tired after walking too long, so he wants to stop _____ a rest.
[ ]
A. having
B. had
C. has
D. to have
世界上最大的商品谷物农业生产国是 （ ）
A．中国
B．美国
C．印度
D．俄罗斯
