题目

It’s necessary for us _________ to our parents when we have problems.A. to talk B. talking C. talk 答案：【答案】A【解析】试题分析：句意：对我们来说，遇到困难时，和我们的父母谈一谈是有必要的。根据句型It’s necessary for sb to do sth“对某人来说做某事是必要的”，故此处用动词不定式to talk。故选A。11．已知向量|$\overrightarrow{a}$|=|$\overrightarrow{b}$|=2，$\overrightarrow{a}$与$\overrightarrow{b}$的夹角为$\frac{π}{3}$，若向量$\overrightarrow{m}$满足|$\overrightarrow{m}$-$\overrightarrow{a}$-$\overrightarrow{b}$|=1，则|$\overrightarrow{m}$|的最大值是（　　）A．2$\sqrt{3}$-1B．2$\sqrt{3}$+1C．4D．$\sqrt{6}$+$\sqrt{2}$+1