A Chinese foreign trade expoter exported 30 000 boxes of goods, contracting to ship the goods in each lot during March to August,5 000 boxes each month, payment by confirmed irrevocable letter of credit. The customer duly sent letter of credit on which the total amount are in conformity with the contract, but the shipping clausee indicated "the latest date of shipment is 31st,August, by partial shipment".Our exporter dispatched 5 000boxes in March, 6 000 boxes in April,10 000 boxes in May and 9 000 boxes in June. The customer raised an objection to this.Are the follow analysis correct? ( )