54.

What happens when ice dams break?（）

• A、They may quickly block the river.

• B、The ice covering the river may melt fast.

• C、A larger ice dam may soon be formed.

• D、The areas down the river maybe flooded

What problem do some farmers have?（）

• A、They have no workers to remove fruit trees.

• B、There is little land for growing fruit.

• C、Their crops were badly damaged last year.

• D、It's difficult to harvest their crops.