问题：
[单选] I have four letters to write today and I have finished_________．
I have four letters to write today and I have finished_________．
问题：
[单选] His hands _______ a little as he took up a pen and began to write．
His hands _______ a little as he took up a pen and began to write．
问题：
[单选] ________at his model plane over the weekend，he didn’t complete it．
________at his model plane over the weekend，he didn’t complete it．
问题：
[单选] I looked and looked，and at last I made out two figures moving slowly in the _______.
I looked and looked，and at last I made out two figures moving slowly in the _______.
问题：
[单选] I always regretted not_________ harder when l was young．
I always regretted not_________ harder when l was young．
问题：
[单选] You can borrow that bicycle if you________．
You can borrow that bicycle if you________．
问题：
[单选] Have you ever been to the museum_________ was built last year?
Have you ever been to the museum_________ was built last year?
问题：
[单选] 函数y=f(x)在点x=x0处取得极大值，则必有（ ）
函数y=f(x)在点x=x0处取得极大值，则必有（ ）
问题：
[单选] 下列函数中，在x=0处不可导的是（ ）
下列函数中，在x=0处不可导的是（ ）
问题：
[单选] 两封信随机地投入标号为1，2，3，4的4个邮筒，则1，2号邮筒各有一封信的概率等于
两封信随机地投入标号为1，2，3，4的4个邮筒，则1，2号邮筒各有一封信的概率等于
