[单选题]为保证安全，救生艇、救助艇考舷梯，最好选择海上（）靠最佳。

正确答案 ：A

海面较平稳时

[单选题]Every liquid has a pressure at which it will vaporize and this pressure varies with temperatureThe word “which” means _____.

正确答案 ：B

a pressure

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