水具每平方厘米的细菌总数不得超过（）个。
A.3
B.4
C.5
D.6
参考答案：C
Deep-draught vessels and VLCCs shall allow for（）of at least 3.5 m at all times during the entire passage through the Straits of Malacca and Singapore.
A.a draft
B.a freeboard
C.an air draft
D.an under-keel clearance
