Children’s brains can’t develop properly they lack protein
A. when B .since C. because D. unless
Children’s brains can’t develop properly they lack protein
A. when B .since C. because D. unless
A
本题中when引导的是一个条件状语从句,相当于if。句意:如果孩子缺少蛋白质,他们的大脑就会发育不良。