1. When the university suggested _______, the student union protested vigorously.  A. tuition be raised   B. to raise tuition   C. on raising tuition   D. that tuition should raise 2. ______ one after another, parallel computers perform groups of operations at the same time.  A. Conventional computers, by handling tasks    B. Since tasks being handled by conventional computers  C. Whereas conventional computers handle tasks   D. While tasks handled by conventional computers 3. ______ the Christmas shopping season begins.  A. That is after Thanksgiving   B. After Thanksgiving it is  C. It is after Thanksgiving that   D. It is Thanksgiving that 4. He promised her an Oxford dictionary, but disappointingly he _______ on his word.  A. turned over    B. stood up   C. went back    D. sat down 5. This young music composer is very famous _______ the most influential composer.  A. for    B. to   C. as   D. with 6. She came ______ a lot of problems at work.  A. up with    B. down with    C. in for   D. up against  chọn đáp án và giải thích chi tiết giúp mình với các bạn ơi