1 . Large quantities of water in the lake have been polluted, terrible smell ______(come) out from time to time. (所给词的适当形式填空)

2 . There is no need for you to look up every new word you ______ when reading. You have to learn how to guess the meanings of new word according to the context.

A．come up with

B．come out

C．come along with

D．come across