According to the author, as for the wave of immigrants, what attitude should Europeans adopt?

(单选题)Statistics ______ a rather modern branch of mathematics. (单选题)A research shows that raising a pet can ______ people ______ (单选题)—Goodbye, John. Come back again sometime.—Sure. ______. (单选题)The letters for the manager ______ on his desk but he didn’t (单选题)The dog seems very quiet now, but he still ______ go by. (单选题)We’d visited the village without advance notice and selected (单选题)Palace Museum and Potala Palace are ______ to be placed on t (单选题)The boy raised in the countryside has made ______ as those b (单选题)It was not until mum agreed to take him to the zoo, ______wa (单选题)I found ______ very easy to learn English well if you put yo