选择正确的单词填空。

1. There ______________ (is, are) seven days in a week.

2. There______________ (is, isn't) any milk in the bottle.

3. There ______________ (are, is) no books on the shelf.

4. There______________ (is, was) an English exam in our class yesterday.

5. How many days ______________ (there are, are there) in a year?

T1加权图像中()

A．只包括T1的成分

B．包括T1和T2的成分

C．包括T1和质子密度的成分

D．只包括T2和质了密度的成分

E．除T1成分外，还包括T2和质子密度的成分