问题
选择题
Jane _____ these families of chimps for many years and helped people understand how much they behave like humans.
A．had studied
B．studied
C．studies
D．has studied
答案
答案：D
考查时态。现在完成时表示过去所发生的事情对现在的影响，在本句中体现出来了。句意：Jane已经研究了猩猩家族很多年了，并帮助人们理解猩猩有很多方面都像人类一样。