—Shall we go and _______ hello to the foreign teachers?

—Good idea! Let's go. [ ]

A. say

B. speak

C. talk

D. shout

食品冰点的高低，与其中溶液部分之浓度有关，浓度越高者冰点越低。18.（× ）在-18℃的冻结终温，食品中的水分已达到100%的冻结率。