问题
It is uncertain ________ side effect the medicine will bring about，although about two thousand patients have taken it．[ ]
A:that
B:what
C:how
D:whether
B:what
C:how
D:whether
正确答案是：
同类题型
Mary _____ be in London because I saw her in town just now. [ ]
His strong sense of humor was make everyone in the room burst out laughing.
You’d better not ring me up between 9 and 10I________ an important meeting then” DrLee said
You will find _______ to learn English if you put your heart in it .