Personnel working aloft (above 2metres) should wear（）or other arresting device at all times.

It should be apparent that little or nothing is gained by opening a drain at the same time as or after admitting steamThe above sentence probably means （）.

As mentioned above, C imposes relatively few built - in ways of doing things on the program- mer. Some common tasks, such as manipulating(66),(67), and doing(68)(I/O), are performed by calling on library functions. Other tasks which you might want to do, such as creating or listing directories, or interacting with a mouse, or displaying windows or other(69)elements, or doing color graphics, are not defined by the C language at all. You can do these things from a C program, of course, but you will be calling on services which are peculiar to your programming environment(70), processor, and operating system)and which are not defined by the C standard. Since this course is about portable C programming, it will also be steering clear of facilities not provided in all C environments.

If necessary to avoid collision or allow more time to（）the situation，a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion．

In speed reading, looking at your watch every 5 or 10 minutes ______.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

Do you like your hometown? Why or why not?

Do you think your hometown is a good place for the elderly? Why or why not?

Do you think your hometown is a good place for young people? Why or why not?

Sometimes lights are（）by fog，haze，dust，smoke，or precipitation which may be present at the light，or between the light and the observer，and which is possibly unknown by the observer.

If you do not know the subject, you will not understand what is said or written, even if English is your mother （） what is said or written.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。