A．howeverB．whateverC．whicheverD．if onlyDo what you thin……

单项选择题Living things are ______ cells, and cells do not grow to more than twice the size they were at first.

单项选择题Every director needs an assistant that he can ______ to take care of problems that may occur in his absence.

单项选择题No sooner had I closed the door than somebody started knocking ______ it.

单项选择题If you don t put the milk in the refrigerator, it may ______.

单项选择题They built the wall especially high so that the little boy couldn t ______ it.