Onaverage,thereare800tornadoesintheUSeachyear,

問題詳情：

 On average, there are 800 tornadoes in the US each year, ______ about 80 deaths and 1,500 injuries.

A. have caused         B. causing          C. caused              D. to be causing

【回答】

B

知識點：非謂語動詞

題型：選擇題