Because of ______ high demand for Type AB blood, ______ supplies of it are usually limited.
| A．the; the | B．不填; 不填 | C．不填; the | D．a; the |
Fully ______in preparing teaching assignment at school，she no longer has much time to enjoy the various activities as usual.
| A．occupy | B．occupying |
| C．occupied | D．to occupy |
---Where is your report of this month？
---Oh sorry，I______ to email to you.
| A．forget | B．have forgotten |
| C．forgot | D．was forgetting |
She is always the first staff to go to the office and the last to leave，______ I guess is why she is promoted so quickly.
| A．who | B．which | C．that | D．what |
EBOLA（埃博拉） is said_______ another big health challenge to our humans over the past several months .
| A．becoming | B．to become |
| C．having become | D．to have become |
Nowadays ______idea is always flashing across his mind that he should fix______time for another trip with his family.
| A．the；a | B．an；/ | C．/；a | D．the；/ |