Many people agree that a（1）knowledge of English is a must in (2) international trade today.(1)这里为什么用 a ,请从词法上解释,不要从意思上解释（2）这里为什么不用介词网上的答案我都不满意 所以另外开

x��TMOQ�+��d��5q�e�4R%�@۸i��7�/@,bE�-"������73+�B�{�N�5i������wι�;���s-���C�x$�h�PHImh)E{��&�W���Hhm=��^*Ϣ�prC 'My��L)ᨲ����T(�R�XT�(����ؚ�XX^t�M/_�u�6�����q[u�_m��w�ݡ��ܫ�^�����{��
۩���5+P���f�e�8���֎38`�+�y� ����(�����.��&����ҿn^p�%��me��G*��>q�#w8���ˬ]�Z���6�
X������.�W��yzfMR�O������s�*�w|O�J�#(b�8(��Ӟӽ���p��T���_��ji|ϻ�����09�MW��^f_� Ω�j�պfC{�q(��CkY���5hH0w$�D`��m�U��X�%�$�W��@�>�2pR.��֣AU392O������'V�r#�զ���&K־��(PgVWMV-b(��9�,�Q���f�"��3���IKڅ#� ��HǶE�3m~�|���2r�(5NT?)���<�@ Z�}�>K��o]f�2�_ Rdӏ?d�[�7T�b��qq���r04�z]�����5V�P� {���8+Y�K�[��X�`��P�
��N�[?��٧�>��f�6.X#�E_��~�����p���d�~���G��H�;�2"V1`�w��