某校兴趣小组制作了一个称量物体质量的“浮力秤”： 如图所示，选一厚底直筒形状的玻璃杯，使之开口向上时能在水中竖直漂浮（水足够深）。已知玻璃杯的质量为100g，底面积为20cm²，高度为20cm。求：

（1）玻璃杯内未放物体时，杯子受到的浮力；

（2）玻璃杯内未放物体时浸入水中的深度（即为该浮力秤的零刻度位置）；

（3）此浮力秤的最大刻度（即称量物体的最大质量）是多少？

You are signing on a deck officer，who will be designated as one of the GMDSS operators，before sailing foreign．Which statement is TRUE（）.

A.He/she must have an STCW certificate endorsed as“Valid for Service on Vessels Operating in the GMDSS System”

B.He/she must present either an FCC-issued license or a Coast Guard-issued license

C.You must consult the“List of Qualifications”on the reverse of his/her FCC-issued license

D.His/her Merchant Mariners Document must have an added endorsement as “Radio Electronics Officer”