问题

irst __________ to the market,the computer software was not a success due to its complexity in operation

A:what
B:when
C:where
D:Which

正确答案是：

同类题型

In spring, it is good for you to sleep ________your windows open.

We all write________, even when there’s not much to say

your pets inside as much as you can when the weather is bad.

Compared with his sister, Jerry is even more ______ to, and more easily troubled by, emotional and relationship problems.

Five athletes competed _____the gold medal ____each other the 100-meter _____dash（短跑）.[ ]