The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.

Federal emergency officials are preparing for a U. S. outbreak of foot-and-mouth disease. The U. S. government has added hundreds of inspectors at airports and ports in an effort to keep the disease out, but the battle is made more difficult because of booming global travel and trade. Foot-and-mouth disease affects pigs, cattle and ot her cloven-hoofed animals but is not generally harmfu to humans.
（）against the US outbreak of foot-and-mouth disease.