问题

was a clever boy, and ______ he was fourteen,he had learned advance mathematics by himself

A:accidents that affected many living things
B:air pollution
C:water pollution
D:from which

正确答案是：

同类题型

l remember ______ to the hospital, supported by my class teacher when I was ill at school.

Miss Smith is very kind. We all like .

Her name is Mary Brown. _____ is her family name.

Jane has been so ________ to getting used to everything that she hasn’t had time for social activities.

What does your brother look like —________.