单项选择题 In many installations basket strainers consist of a cylindrical container in which a perforated metal or wire basket is suspendedThe bold and italic word “which” means （）.

单项选择题 Strainers, sometimes called （）, are devices designed to prevent the passage of unwanted solids into or further along a system.

单项选择题 A(n) （） is a special type of valve which prevents the passage of steam but allows condensate to pass.