According to the Chemical Data Guide，which reactive group(s) is/are not compatible with the products polybutene and o-xylene? （）

单项选择题According to the Chemical Data Guide，1，3 - pentadiene possesses which characteristic? （）

A.Colorless liquid，mild aromatic odor
B.Pale yellow liquid，strong odor
C.Colorless liquid，faint odor
D.Straw-colored liquid，sweet-odor

单项选择题According to regulations，access to a cargo pumproom in a tank vessel carrying grades C or D liquid cargo shall be（）.

A.from areas equipped with power ventilation
B.only from enclosed areas free from sources of vapor ignition
C.from the open deck
D.from within the vessel

单项选择题Access to a cargo pumproom on a tank vessel carrying grades A，B，C or D liquid cargoes shall be（）.

A.at least 13.1 feet away from the galleys，living quarters or navigation spaces
B.from the open deck
C.only from areas equipped with power ventilation systems
D.isolated from any part of the vessel which normally contains sources of vapor ignition

单项选择题A synonym for chloroform is（）.

A.trichloromethane
B.sulfuric chlorohydrin
C.chlorine gas
D.4-methyl phenol

单项选择题A safe fuel system must（）.

A.prevent engine overheating
B.have proper air/gasoline fuel mixture ratio
C.be liquid- and vapor-tight
D.supply sufficient air to the intake manifold