In this task, you are given a word, followed by a sentence. You should respond with a valid sentence which contains the word with the same meaning as in the given sentence. For example, if the given sentence refers to a 'fly' as the insect, you should not respond with a sentence which uses 'fly' as the verb. You may use the word in a different tense than is given. For example, you may use the word 'ended' in the output where the given input word is 'end'.

Let me give you an example: dust 
 Sentence: Another one bites the dust.
The answer to this example can be:  The maid used a handkerchief to remove dust off the table.
Here is why: In both the input and output sentences, the word 'dust' refers to sand, and therefore the words share the same meaning.

OK. solve this:
guard 
 Sentence: Guard against infection.
Answer:
Guard against becoming too friendly with the staff.