He is so careless that he always _________ his school things at home.

He is so careless that he always _________ his school things at home.

答案C
由句意可知“他总是把学习用品丢在家里”，而把东西丢在某处习惯用leave sth. somewhere；又因为本句说明的是一般现在情况，故用一般现在时。因此选C。