"The process control functions are Unix-only: true or false" True.
"Using pcntl_fork() is a good way to do multi-threading: true or false" True - or at least it's as good as you're likely to find!
"The pcntl_exec() function is functionally the same as the exec() function: true or false" False. The former actually replaces the PHP process that called it with the new child process.
"Which SPL interface lets you use your object as an array" The answer is "b", ArrayAccess.
"What is the filename that needs to be downloaded to use browser detection" Browscap.ini is the file you're after.
"What does bcpowmod() do" The answer is "d": it multiplies a number by itself, then divides it and returns the remainder.
"Templates make the job of separating design from layout easier: true or false" False: design and layout are the same thing! Templates separate design from content, maybe, or design from logic, but never design from layout.