The author thought the harbormaster and RNLI were angry with him maybe because
A. he wasted time and money on surfing.
B. he menaced coastguards coming to aid.
C. he didn"t need them to rescue him.
D. he destroyed a boat in the waves.
查看答案
聚酰胺制件的脱模剂最好用()。
A 硬脂酸锌
B 液体石蜡
C 蓖麻油
D 植物油
为了方便取件，能将积存在模嘴内的冷料连同主浇道的料柱一起拉出，要求喷嘴口直 径d应()衬套主浇道直径d0。
A 稍小于
B 稍大于
C 等于
According to the passage, scientists examine the genomes of astronauts in order to
A. select suitable astronauts for the space flight.
B. design countermeasures against gene mutation.
C. detect and cure the deficiencies in their genes.
D. prepare personalized gene-based medicine.
下面哪些零件不属于支承零件()。
A 动模座板
B 垫块
C 推板
D支承板
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