C time permitting 为正确选项.
这是“名词或代词+现在分词”结构,属于独立主格结构的一种形式,做条件状语.相当于一个条件状语从句If time permits...35 when a pencil is partly in a glass of water ,it look as if it _.A breaks B has broken C were broken D had been broken36.it is necessary that she _ once a week to heip me with my lessonAcame B would come C come D comes.37.the question is _it is worth doing.A if B whether C which Dwhat38_ knows the truth will tell you about it .A who that B whoeverC whom that D that who