20.（ ）

(单选题)—Are you enjoying your life here?—Yes, very much. I wish I _ (单选题)Be sure to write to us, ______? (单选题)______ the numbers of such developments are relatively small (单选题)China is sure to further reduce the poor rural population by (单选题)In the global economy, a new drug for cancer, ______ it is d (单选题)______ the price may be, they are prepared to pay it. (单选题)The students stopped talking ______ Mr. Brown stepped into t (单选题)Even though yerba mate, the national drink of Argentina, is (单选题)Many netizens are impressed with the excuse given by a teach (单选题)I’ll show you a shop ______ you may buy all ______ you need.