【填空题】土壤矿物质一般分为（）、（）、（）和（）四个基本粒级。

A、Sir Gawain and the Green Knight

B、The Song of Beowulf

C、Piers, the Plowman

D、he Canterbury Tales

A、承诺

B、要约

C、要约邀请

A、细胞毒性

B、辅助性

C、抑制性

D、兴奋性

A、good for farmers because it raises prices for their products but bad for consumers because it raises prices consumers pay for food.

B、bad for farmers because total revenue will fall but good for consumers because prices for food will fall.

C、good for farmers because it raises prices for their products and also good for consumers because more output is available for consumption.

D、bad for farmers because total revenue will fall and bad for consumers because farmers will raise the price of food to increase their total revenue.

A、有效水

B、无效水

A、白天开放口岸

B、全天候口岸

C、季节性口岸

D、夜间开放口岸

A、心血管系统和淋巴系统

B、心血管系统和生殖系统

C、心血管系统和内分泌系统

D、心血管系统和呼吸系统