B
【解析】
试题分析：题目考查时态。句意：我已经看完了这本英文小说的一半，周末会尽力把另一半看完。发生在过去的动作对现在产生影响，用现在完成时。“看小说”这一动作发生在过去，到目前为止看了一半，故用完成时，故选B。
考点：考查时态
【名师点睛】
现在完成时基本用法：
1、表示过去发生或已经完成的动作对现在造成的影响或结果，常与already, yet, ever, never, just，before 等词连用。
例如：Have you ever cooked at home? 你吃晚饭了吗？
You have already grown much taller.你已经长高了许多。
2、表示过去已经开始，持续到现在的动作或状态。往往和表示一段时间的时间状语连用，常用的有：for＋一段时间；since+过去时间点或从句。（Since 用来说明动作起始时间，for用来说明动作延续时间长度），提问用How long.
例如：It has been five years since he joined the army .他参军五年了。
They have learned English for eight years .他们已学了八年的英语了。
3、现在完成时需注意的问题：
○1表示短暂性的动词不能与表示一段时间的状语连用appear, begin, borrow, lend, buy, close,
come, die, fall, find, finish, join, kill, leave, sell, stop等。
例如：He has joined the army for five years. （错误）
He has been in the army for five years.(正确)
注意：非延续性动词的否定形式可以与表示延续时间的状语连用。即动作不发生的状态是可以持续的。
（错）I have received his letter for a month.
（对）I haven't received his letter for almost a month.
○2不能和明确的过去时间状语连用，如：yesterday, last week, in 1998,two days ago等。
○3have/has been to 和have/has gone to 的区别：
have/has been to 去过某地，现在已经回来；
have/has gone to 去了某地，在去的路上或已经在那里。
I saw this film yesterday. （强调看的动作发生过了）
I have seen this film. （强调对现在的影响，电影的内容已经知道了）
Why did you get up so early? （强调起床的动作已发生过了）
He has been a League member for three years. （强调他是团员）
现在完成时考点分析：
①现在完成时除可以和for、since引导的状语连用外，还可以和下面的介词短语连用：during / in /over the last(past)few years (months, weeks)、in recent years等。
②下列句型中常用现在完成时
It is (has been) + 一段时间 + since从句
This(That / It)is the first(second…)time that + 完成时
This(That / It)is the only … + that + 完成时
This(that / It)is the best / finest / most interesting … + that 从句 + 完成时
③在时间或条件状语从句中，现在完成时可以代替一般将来时。如：
I shall post the letter as soon as I have written it.
If you have done the experiment, you will realize the theory better.
Don’t get off the bus until it has stopped.
